diff --git a/packages/stage-ui/src/libs/auth-fetch.ts b/packages/stage-ui/src/libs/auth-fetch.ts
index 4a595f5ee..5c5c0c7b4 100644
--- a/packages/stage-ui/src/libs/auth-fetch.ts
+++ b/packages/stage-ui/src/libs/auth-fetch.ts
@@ -10,6 +10,12 @@ import { getAuthToken } from './auth'
  * suspended tabs, and the post-reload race (fetchSession firing before
  * restoreRefreshSchedule resolves) can all leak an expired Bearer through.
  * The reactive 401 path is the safety net.
+ *
+ * When refresh cannot succeed — missing state (refreshToken/oidcClientId),
+ * refresh endpoint errors, or a retried request that still returns 401 —
+ * clear local auth state and flip `needsLogin` so the user is prompted to
+ * sign in immediately, instead of letting the dead session linger until the
+ * next fetchSession call on the home page.
  */
 export async function authedFetch(
   input: RequestInfo | URL,
@@ -33,9 +39,20 @@ export async function authedFetch(
   if (url.includes('/oauth2/token'))
     return response
 
-  const newToken = await useAuthStore().refreshTokenNow()
-  if (!newToken)
+  const authStore = useAuthStore()
+  const newToken = await authStore.refreshTokenNow()
+  if (!newToken) {
+    promptReLogin(authStore)
     return response
+  }
 
-  return doFetch(newToken)
+  const retried = await doFetch(newToken)
+  if (retried.status === 401)
+    promptReLogin(authStore)
+  return retried
+}
+
+function promptReLogin(authStore: ReturnType<typeof useAuthStore>): void {
+  authStore.clearAllAuthState()
+  authStore.needsLogin = true
 }
diff --git a/packages/stage-ui/src/libs/auth.ts b/packages/stage-ui/src/libs/auth.ts
index e0b1cea1d..bc21837a6 100644
--- a/packages/stage-ui/src/libs/auth.ts
+++ b/packages/stage-ui/src/libs/auth.ts
@@ -45,12 +45,29 @@ export async function initializeAuth() {
 
   initialized = true
 
+  const authStore = useAuthStore()
+
+  // Normalize "half-cleared" persisted state before anything reads it.
+  //
+  // Why: `refreshToken` was added to the auth store before `oidcClientId`
+  // (commit c73ceeb1f predates f1fe161bc), and `clearOIDCState` (now removed)
+  // used to clear only the OIDC pair. Browsers that saw either code path can
+  // end up with a refreshToken but no oidcClientId, which makes
+  // `refreshTokenNow()` early-return forever — 401s then silently accumulate
+  // on non-home pages until the user lands on a route that calls fetchSession.
+  //
+  // Treat any mismatch as an unauthenticated session; the user will get a
+  // fresh OIDC login prompt via the standard 401→needsLogin path.
+  const hasRefreshToken = !!authStore.refreshToken
+  const hasClientId = !!authStore.oidcClientId
+  if (hasRefreshToken !== hasClientId)
+    authStore.clearAllAuthState()
+
   // NOTICE: restoreRefreshSchedule must complete BEFORE fetchSession when
   // the persisted access token is already expired. Otherwise fetchSession
   // hits /get-session with the stale Bearer, gets 401, and wipes
   // refreshToken + oidcClientId before the scheduled refresh can run —
   // silently logging the user out on reload.
-  const authStore = useAuthStore()
   authStore.onTokenRefreshed(async (accessToken) => {
     authStore.token = accessToken
     await fetchSession()
@@ -94,11 +111,7 @@ export async function fetchSession() {
   }
 
   // Session expired or invalid — clear stale auth state from localStorage
-  authStore.user = null
-  authStore.session = null
-  authStore.token = null
-  authStore.refreshToken = null
-  authStore.clearOIDCState()
+  authStore.clearAllAuthState()
   return false
 }
 
@@ -162,11 +175,7 @@ export async function signOut() {
     // be wiped, so the local user has no way to spend it in the meantime.
   }
 
-  authStore.clearOIDCState()
-  authStore.user = null
-  authStore.session = null
-  authStore.token = null
-  authStore.refreshToken = null
+  authStore.clearAllAuthState()
 }
 
 /**
diff --git a/packages/stage-ui/src/stores/auth.ts b/packages/stage-ui/src/stores/auth.ts
index 405bf9068..e0a05c343 100644
--- a/packages/stage-ui/src/stores/auth.ts
+++ b/packages/stage-ui/src/stores/auth.ts
@@ -151,13 +151,7 @@ export const useAuthStore = defineStore('auth', () => {
         return tokens.access_token
       }
       catch {
-        user.value = null
-        session.value = null
-        token.value = null
-        refreshToken.value = null
-        idToken.value = null
-        oidcClientId.value = null
-        tokenExpiry.value = null
+        clearAllAuthState()
         return null
       }
       finally {
@@ -176,6 +170,11 @@ export const useAuthStore = defineStore('auth', () => {
 
   function scheduleTokenRefresh(expiresInSeconds: number): void {
     stopRefreshTimer()
+    // Guard against missing/invalid lifetimes (e.g. token response omitted
+    // expires_in). useTimeoutFn with NaN/<=0 delay would fire immediately
+    // and spin a refresh loop — skip scheduling instead.
+    if (!Number.isFinite(expiresInSeconds) || expiresInSeconds <= 0)
+      return
     // Refresh at 80% of lifetime
     refreshDelayMs.value = expiresInSeconds * 0.8 * 1000
     startRefreshTimer()
@@ -212,8 +211,23 @@ export const useAuthStore = defineStore('auth', () => {
     }
   }
 
-  function clearOIDCState(): void {
+  /**
+   * Reset every auth-related field atomically.
+   *
+   * Use when: signing out, refresh fails, session is rejected by server, or
+   * persisted state is detected inconsistent.
+   *
+   * Why atomic: `refreshToken` and `oidcClientId` must either both exist or
+   * both be absent. A "half-cleared" state (one present, one null) makes
+   * `refreshTokenNow()` early-return without attempting refresh, so 401s
+   * loop silently until the user lands on a page that calls fetchSession.
+   */
+  function clearAllAuthState(): void {
     stopRefreshTimer()
+    user.value = null
+    session.value = null
+    token.value = null
+    refreshToken.value = null
     oidcClientId.value = null
     tokenExpiry.value = null
     idToken.value = null
@@ -260,7 +274,7 @@ export const useAuthStore = defineStore('auth', () => {
     scheduleTokenRefresh,
     restoreRefreshSchedule,
     refreshTokenNow,
-    clearOIDCState,
+    clearAllAuthState,
     onTokenRefreshed,
   }
 })