diff --git a/frontend/src/hooks/useChatSync.ts b/frontend/src/hooks/useChatSync.ts
index 629be5812..fb9514885 100644
--- a/frontend/src/hooks/useChatSync.ts
+++ b/frontend/src/hooks/useChatSync.ts
@@ -27,11 +27,8 @@ const useAgentHealthOnReconnect = (check: () => void): void => {
 const currentHandoff = () => toChatHandoff(store.getState().chat)
 
 /* The identity the chat is scoped by. auth.user, NOT the persisted `user` model: auth.user is
-   fetched for the CURRENT tokens at sign-in (it is what lets App mount), while the user model
-   is restored from storage and only catches up when the cloud sync lands. Activating a saved
-   account swaps tokens and reloads without purging persisted models, so for that interval
-   (indefinitely, if the sync stalls) the user model still names the PREVIOUS account — and an
-   ownership check against it would keep that account's transcript on the new account's screen. */
+   fetched for the CURRENT tokens at sign-in (it is what lets App mount), while the rest of the
+   user model is restored from storage and only catches up when the cloud sync lands. */
 const useChatIdentity = (): string => useSelector((state: State) => state.auth.user?.id ?? '') // '' = not signed in: syncIdentity no-ops
 
 /* What both chat surfaces do on boot: follow the signed-in identity, clear what must not
diff --git a/frontend/src/models/auth.test.ts b/frontend/src/models/auth.test.ts
index 9a750564a..b9e70c612 100644
--- a/frontend/src/models/auth.test.ts
+++ b/frontend/src/models/auth.test.ts
@@ -51,7 +51,7 @@ const {
   oidcMcpDetailReady: vi.fn(),
   pushUnregister: vi.fn(),
   browser: { isElectron: false, hasBackend: false },
-  storeState: { auth: {} as Record<string, unknown> },
+  storeState: { auth: {} as Record<string, unknown>, user: { id: '' } },
 }))
 
 // signInFailure() tests `error instanceof OidcError`, so the mock must export a real class
@@ -74,9 +74,11 @@ vi.mock('../services/oidc', () => ({
 }))
 vi.mock('../helpers/stageHelper', () => ({ chooseStage, reloadIfStageChanged }))
 vi.mock('../services/permitteerAccount', () => ({ signOutEverywhere }))
+const { broadcastChatSignout } = vi.hoisted(() => ({ broadcastChatSignout: vi.fn() }))
+vi.mock('../services/chatPopout', () => ({ broadcastChatSignout }))
 vi.mock('../services/accountSecurity', () => ({ changePassword }))
 vi.mock('../services/Controller', () => ({
-  default: { close: controllerClose, emitWithAck, reconnectNow },
+  default: { close: controllerClose, emitWithAck, reconnectNow, setupConnection: vi.fn() },
   emit: vi.fn(() => false),
 }))
 vi.mock('../services/CloudSync', () => ({ default: { reset: vi.fn() } }))
@@ -89,8 +91,23 @@ vi.mock('../services/pushNotifications', () => ({ default: { register: vi.fn(),
 vi.mock('../services/graphQLRequest', () => ({ graphQLLogin: vi.fn() }))
 vi.mock('../services/remoteit', () => ({ getToken: vi.fn(), apiAuthHeaders: vi.fn() }))
 vi.mock('../selectors/devices', () => ({ selectDeviceModelAttributes: vi.fn() }))
+const persist = vi.hoisted(() => ({
+  bootstrapped: true,
+  persistsState: true,
+  listener: undefined as undefined | (() => void),
+}))
 vi.mock('../store', () => ({
-  persistor: { purge: vi.fn() },
+  get persistsState() {
+    return persist.persistsState
+  },
+  persistor: {
+    purge: vi.fn(),
+    getState: () => ({ bootstrapped: persist.bootstrapped }),
+    subscribe: (listener: () => void) => {
+      persist.listener = listener
+      return () => (persist.listener = undefined)
+    },
+  },
   store: { getState: () => storeState, dispatch: { auth: { completeCallback } } },
 }))
 vi.mock('../i18n', () => ({ default: { t: (k: string) => k } }))
@@ -114,6 +131,18 @@ function makeDispatch() {
   }
 }
 
+// Every model and method on demand, as a spy: for effects that fan out across many models.
+function spyDispatch() {
+  const models: Record<string, Record<string, ReturnType<typeof vi.fn>>> = {}
+  const dispatch = new Proxy(models, {
+    get: (all, model: string) =>
+      (all[model] ??= new Proxy({} as Record<string, ReturnType<typeof vi.fn>>, {
+        get: (calls, fn: string) => (calls[fn] ??= vi.fn()),
+      })),
+  })
+  return { models, dispatch: dispatch as any }
+}
+
 // The only shape SignInApp renders: it shows a message ONLY while signInFailed is true, and
 // signInFailed is also the brake on auto sign-in — so every failure writer must produce it.
 const aFailureShowing = (signInError: string) => expect.objectContaining({ signInFailed: true, signInError })
@@ -121,6 +150,8 @@ const aFailureShowing = (signInError: string) => expect.objectContaining({ signI
 // eslint-disable-next-line @typescript-eslint/no-var-requires
 import authModel, { liveAuthCallback } from './auth'
 import { agentOwnedMessage } from '@common/agentOwner'
+import { graphQLLogin } from '../services/graphQLRequest'
+import { PERSISTED_MODELS } from './persistedModels'
 
 const effectsFor = (dispatch: any) => (authModel as any).effects(dispatch)
 
@@ -403,13 +434,7 @@ describe('auth model — a stage switch signs out and reloads onto the new stage
   })
 
   it('the sign-out teardown reloads onto a changed stage as its last step', async () => {
-    const fns: Record<string, Record<string, ReturnType<typeof vi.fn>>> = {}
-    const dispatch = new Proxy(fns, {
-      get: (models, model: string) =>
-        (models[model] ??= new Proxy({} as Record<string, ReturnType<typeof vi.fn>>, {
-          get: (calls, fn: string) => (calls[fn] ??= vi.fn()),
-        })),
-    })
+    const { dispatch } = spyDispatch()
     await effectsFor(dispatch).signedOut()
     expect(reloadIfStageChanged).toHaveBeenCalledTimes(1)
     expect(controllerClose.mock.invocationCallOrder[0]).toBeLessThan(reloadIfStageChanged.mock.invocationCallOrder[0])
@@ -659,6 +684,88 @@ describe('auth model — the desktop hands the chooser callback to a signed-in w
   })
 })
 
+describe('auth model — signing in as another account clears the last account’s persisted state', () => {
+  const signInAs = async (id: string, persistedOwner: string) => {
+    storeState.user = { id: persistedOwner }
+    vi.mocked(graphQLLogin).mockResolvedValue({
+      data: { data: { login: { id, authhash: 'hash', yoicsId: 'yoics' } } },
+    } as any)
+    const { dispatch } = spyDispatch()
+    await effectsFor(dispatch).fetchUser()
+    return dispatch
+  }
+
+  beforeEach(() => broadcastChatSignout.mockReset())
+
+  afterEach(() => {
+    storeState.user = { id: '' }
+    persist.bootstrapped = true
+    persist.persistsState = true
+  })
+
+  it('resets and closes chat popouts before the new user is set when the persisted state is another account’s', async () => {
+    const dispatch = await signInAs('USER-B', 'USER-A')
+    expect(dispatch.auth.resetAccountData).toHaveBeenCalledTimes(1)
+    expect(broadcastChatSignout).toHaveBeenCalledTimes(1)
+    expect(dispatch.auth.resetAccountData.mock.invocationCallOrder[0]).toBeLessThan(
+      dispatch.auth.set.mock.invocationCallOrder[0]
+    )
+  })
+
+  it('stamps the new owner right after the reset, before any account fetch can persist', async () => {
+    const dispatch = await signInAs('USER-B', 'USER-A')
+    expect(dispatch.user.set).toHaveBeenCalledWith({ id: 'USER-B' })
+    expect(dispatch.auth.resetAccountData.mock.invocationCallOrder[0]).toBeLessThan(
+      dispatch.user.set.mock.invocationCallOrder[0]
+    )
+  })
+
+  it('keeps the persisted state and chat popouts for the same account', async () => {
+    const dispatch = await signInAs('USER-A', 'USER-A')
+    expect(dispatch.auth.resetAccountData).not.toHaveBeenCalled()
+    expect(broadcastChatSignout).not.toHaveBeenCalled()
+  })
+
+  it('treats state with no recorded owner as another account’s, popouts included', async () => {
+    const dispatch = await signInAs('USER-A', '')
+    expect(dispatch.auth.resetAccountData).toHaveBeenCalledTimes(1)
+    expect(broadcastChatSignout).toHaveBeenCalledTimes(1)
+    expect(dispatch.user.set).toHaveBeenCalledWith({ id: 'USER-A' })
+  })
+
+  it('skips the check in a popout or support tab, which persists nothing and must not close other windows’ popouts', async () => {
+    persist.persistsState = false
+    const dispatch = await signInAs('USER-A', '')
+    expect(dispatch.auth.resetAccountData).not.toHaveBeenCalled()
+    expect(broadcastChatSignout).not.toHaveBeenCalled()
+    expect(dispatch.user.set).toHaveBeenCalledWith({ id: 'USER-A' })
+  })
+
+  it('waits for rehydration before reading the owner', async () => {
+    persist.bootstrapped = false
+    vi.mocked(graphQLLogin).mockResolvedValue({
+      data: { data: { login: { id: 'USER-B', authhash: 'h', yoicsId: 'y' } } },
+    } as any)
+    const { dispatch } = spyDispatch()
+    const signingIn = effectsFor(dispatch).fetchUser()
+    await vi.waitFor(() => expect(persist.listener).toBeDefined())
+    expect(dispatch.auth.set).not.toHaveBeenCalled()
+
+    storeState.user = { id: 'USER-A' }
+    persist.bootstrapped = true
+    persist.listener?.()
+    await signingIn
+    expect(dispatch.auth.resetAccountData).toHaveBeenCalledTimes(1)
+  })
+
+  it('resets every persisted model', () => {
+    const { models, dispatch } = spyDispatch()
+    effectsFor(dispatch).resetAccountData()
+    const reset = Object.keys(models).filter(model => models[model].reset?.mock.calls.length)
+    expect(reset.sort()).toEqual([...PERSISTED_MODELS].sort())
+  })
+})
+
 describe("auth model — a different account arriving drops this phone's push token", () => {
   beforeEach(() => {
     oidcClaims.mockReset().mockReturnValue({ sub: 'sub-a' })
diff --git a/frontend/src/models/auth.ts b/frontend/src/models/auth.ts
index 4495a1757..7e121d6e2 100644
--- a/frontend/src/models/auth.ts
+++ b/frontend/src/models/auth.ts
@@ -14,11 +14,12 @@ import {
   StageName,
 } from '../constants'
 import { chooseStage, reloadIfStageChanged } from '../helpers/stageHelper'
-import { persistor, store } from '../store'
+import { persistor, persistsState, store } from '../store'
 import { graphQLLogin } from '../services/graphQLRequest'
 import { getToken } from '../services/remoteit'
 import { changePassword as changeAccountPassword } from '../services/accountSecurity'
 import { signOutEverywhere } from '../services/permitteerAccount'
+import { broadcastChatSignout } from '../services/chatPopout'
 import {
   oidcConfigured,
   oidcSignedIn,
@@ -116,6 +117,17 @@ const signInFailure = (error: any): Partial<AuthState> => ({
   signInRetryAfter: error instanceof OidcError ? error.retryAfter : undefined,
 })
 
+// auth.init is not gated on rehydration, and an owner read before it sees the empty default.
+const rehydrated = () =>
+  new Promise<void>(resolve => {
+    if (persistor.getState().bootstrapped) return resolve()
+    const unsubscribe = persistor.subscribe(() => {
+      if (!persistor.getState().bootstrapped) return
+      unsubscribe()
+      resolve()
+    })
+  })
+
 const signInCleared = {
   signInFailed: false,
   signInError: undefined,
@@ -302,6 +314,17 @@ export default createModel<RootModel>()({
 
       const user = response?.data?.data?.login
 
+      // Switching accounts reloads without signing out, so a window's persisted state, and any chat popout still paired
+      // with it, can be the last account's. With no owner recorded neither can be trusted.
+      await rehydrated()
+      const owner = store.getState().user.id
+      if (persistsState && user?.id && owner !== user.id) {
+        auth.resetAccountData()
+        broadcastChatSignout()
+      }
+      // Stamped here rather than when user.fetch lands, so a second switch before then still sees an owner.
+      if (user?.id) dispatch.user.set({ id: user.id })
+
       auth.set({ user, ...signInCleared })
       if (user.authhash && user.yoicsId) {
         Controller.setupConnection({ username: user.yoicsId, authHash: user.authhash, guid: user.id })
@@ -512,29 +535,14 @@ export default createModel<RootModel>()({
          a stale error and no redirect, for something that happened in someone else's
          session. */
       await dispatch.auth.set({ user: undefined, ...signInCleared })
-      dispatch.chat.reset()
+      dispatch.auth.resetAccountData()
       dispatch.agents.reset()
-      dispatch.user.reset()
-      dispatch.organization.reset()
-      dispatch.networks.reset()
-      dispatch.accounts.reset()
-      dispatch.connections.reset()
-      dispatch.devices.reset()
-      dispatch.sessions.reset()
       dispatch.logs.reset()
       dispatch.search.reset()
-      dispatch.announcements.reset()
-      dispatch.applicationTypes.reset()
-      dispatch.plans.reset()
-      dispatch.contacts.reset()
       dispatch.billing.reset()
       dispatch.backend.reset()
-      dispatch.files.reset()
       dispatch.keys.reset()
-      dispatch.jobs.reset()
-      dispatch.tags.reset()
       dispatch.ui.reset()
-      dispatch.products.reset()
       dispatch.partnerStats.reset()
       dispatch.adminUsers.reset()
       dispatch.adminPartners.reset()
@@ -556,6 +564,25 @@ export default createModel<RootModel>()({
       Controller.close()
       reloadIfStageChanged()
     },
+    /** Every persisted model: what sign-out clears, and what a sign-in finding another account's state clears. */
+    resetAccountData() {
+      dispatch.chat.reset()
+      dispatch.user.reset()
+      dispatch.organization.reset()
+      dispatch.networks.reset()
+      dispatch.accounts.reset()
+      dispatch.connections.reset()
+      dispatch.devices.reset()
+      dispatch.sessions.reset()
+      dispatch.announcements.reset()
+      dispatch.applicationTypes.reset()
+      dispatch.plans.reset()
+      dispatch.contacts.reset()
+      dispatch.files.reset()
+      dispatch.jobs.reset()
+      dispatch.tags.reset()
+      dispatch.products.reset()
+    },
     /** Test Settings' stage switch. This signs out of the old login server; the reload at the end of
      *  signedOut boots every endpoint on the new stage, where init drops the old stage's accounts. */
     async switchStage(stage: StageName, state) {
diff --git a/frontend/src/models/persistedModels.ts b/frontend/src/models/persistedModels.ts
new file mode 100644
index 000000000..54e416b0f
--- /dev/null
+++ b/frontend/src/models/persistedModels.ts
@@ -0,0 +1,18 @@
+export const PERSISTED_MODELS = [
+  'accounts',
+  'announcements',
+  'applicationTypes',
+  'chat',
+  'connections',
+  'contacts',
+  'devices',
+  'files',
+  'jobs',
+  'networks',
+  'organization',
+  'plans',
+  'products',
+  'sessions',
+  'tags',
+  'user',
+] as const
diff --git a/frontend/src/store.ts b/frontend/src/store.ts
index b89c1bf64..5e1c628c3 100644
--- a/frontend/src/store.ts
+++ b/frontend/src/store.ts
@@ -2,11 +2,13 @@ import { numericVersion } from './helpers/versionHelper'
 import { models, RootModel } from './models'
 import { defaultChatState, IChatState } from './models/chat'
 import { isChatPopout, popoutScopeId } from './services/chatPopout'
+import { oidcIsSupportTab } from './services/oidc'
 import { createLogger, ReduxLoggerOptions } from 'redux-logger'
 import { init, RematchDispatch, RematchRootState } from '@rematch/core'
 import { createTransform, PersistConfig } from 'redux-persist'
 import persistPlugin, { getPersistor } from '@rematch/persist'
 import DateTransform from './helpers/DateTransform'
+import { PERSISTED_MODELS } from './models/persistedModels'
 import immerPlugin from '@rematch/immer'
 import localForage from 'localforage'
 
@@ -43,29 +45,14 @@ const noopStorage = {
   removeItem: () => Promise.resolve(),
 }
 
+export const persistsState = !isChatPopout && !oidcIsSupportTab()
+
 const persistConfig: PersistConfig<RootModel> = {
   key: 'app',
   version: numericVersion(),
-  // The popout persists nothing (noopStorage) so it cannot clobber the main window's 'app' key.
-  storage: isChatPopout ? noopStorage : localForage,
-  whitelist: [
-    'accounts',
-    'announcements',
-    'applicationTypes',
-    'chat',
-    'connections',
-    'contacts',
-    'devices',
-    'files',
-    'jobs',
-    'networks',
-    'organization',
-    'plans',
-    'products',
-    'sessions',
-    'tags',
-    'user',
-  ],
+  // The popout and support tabs persist nothing (noopStorage), so neither can clobber the main window's 'app' key.
+  storage: persistsState ? localForage : noopStorage,
+  whitelist: [...PERSISTED_MODELS],
   throttle: 1000,
   transforms: [DateTransform, chatTransform],
 }