Cracked keycard and padlock symbolizing unstable login sessions
If Firefox on Android keeps signing you out, forgetting you between tabs, or sending you through a sign-in loop, it’s almost always a “session” problem: the site can’t keep (or read) the cookie/token that proves you already logged in.

That sounds technical, but the fixes are usually simple once you match the symptom to the cause.

This article uses a symptom → cause → fix mapping, so you can jump straight to the pattern you’re seeing.

Quick note: try these steps first on one affected site (not all sites), so you can tell which change actually helped.

1. Symptom: You log in successfully, but you’re logged out again minutes later

Likely cause: Enhanced Tracking Protection (ETP) or a strict cookie policy is blocking a key session cookie (sometimes third‑party, sometimes “partitioned” storage).

Fix mapping:

  • Test the site in a Private tab. If it works there (or fails differently), it’s a clue that add-ons/site data are involved.
  • Turn off protection for just that site: open the site → tap the shield icon (or site info) → disable Enhanced Tracking Protection for this site → reload.
  • If you use Strict mode: switch ETP to Standard temporarily (Settings → Privacy & Security → Enhanced Tracking Protection) and retest.

Shield blocking a cookie, representing tracking protection effects
If disabling protection for that one site fixes it, you don’t need to weaken privacy everywhere—keep the exception limited to that domain.

2. Symptom: Login loop (you sign in, then it sends you back to sign in again)

Likely cause: corrupted cookies/site storage for that domain, or a blocked redirect/storage step (common with identity providers and embedded login pages).

Fix mapping:

  • Clear site data for only that site (preferred over clearing everything): Settings → Site permissions / Site settings (varies by version) → Data stored / Manage data → find the site → clear.
  • Allow cookies for the session flow: if you’ve blocked cookies globally, allow them (at least temporarily) while you sign in.
  • Disable “Delete browsing data on quit” (if enabled). If Firefox wipes cookies when it closes, sessions can’t persist.

After clearing just the site’s data, close all Firefox tabs for that site and try again from a fresh tab.

3. Symptom: You stay signed in until you switch apps, then you’re logged out when you return

Likely cause: Android battery optimization or memory pressure is killing Firefox, and the site’s session is short-lived unless the app resumes cleanly.

Fix mapping:

  • Disable battery optimization for Firefox: Android Settings → Apps → Firefox → Battery → set to Unrestricted (wording varies by device).
  • Turn off Data Saver (Android or carrier-level) as a test; it can interfere with background network handoffs on some devices.
  • Update Firefox from Google Play. Session persistence bugs do get fixed in point releases.

Battery and toggle symbolizing Android battery optimization settings
If this is the pattern, the goal is not “more cookies”—it’s keeping Firefox stable enough that the session can be resumed normally.

4. Symptom: Only one site logs you out; other sites remember you fine

Likely cause: the site uses a specific identity setup (SSO, embedded provider login, cross-site cookies) that’s more sensitive to tracking protections, VPNs, or content blockers.

Fix mapping:

  • Try without VPN (just for a minute). Some sites invalidate sessions when your IP/location changes mid-session.
  • Check for extensions/add-ons that block scripts, cookies, or headers. Disable them temporarily and retest.
  • Add a site exception rather than changing global privacy settings.

When it’s only one site, treat it as a “compatibility exception” problem, not a browser-wide failure.

5. Symptom: You’re signed in, but the site acts signed out in another tab (tabs disagree)

Likely cause: the site’s session is stored in a way that’s getting partitioned or isolated (especially if the login page and the app page are on different subdomains), or one tab has stale cached state.

Fix mapping:

  • Hard refresh the affected tab (reload) and close duplicate tabs of the same service.
  • Clear site data for that domain, then sign in once (single tab), then open additional tabs.
  • Avoid “Open in app” handoffs during login (if Android offers it). Jumping between app and browser during authentication can break the token exchange.

For services that use multiple subdomains, it sometimes helps to start the login from the site’s main homepage (not a deep link).

6. Symptom: You get logged out after restarting the phone or after Firefox updates

Likely cause: cookies are being cleared on exit, storage is being reclaimed, or the profile data is being reset during an update/migration.

Fix mapping:

  • Confirm Firefox isn’t set to erase data on exit (Settings → Privacy & Security → Delete browsing data on quit).
  • Check Android storage pressure: if your device is extremely low on storage, Android may aggressively clear app caches/data.
  • If you recently used a “cleaner” app or system cleanup, undo/disable it for Firefox—those tools often wipe cookies.

If it started right after an update, also try signing out (on the website), then signing in again once—some sites require a fresh session after a browser engine change.

7. Symptom: It happens on many sites, suddenly, after you changed privacy settings

Likely cause: a global setting is now too aggressive for modern session flows (common culprits: strict protection, cookie blocking, “HTTPS only” edge cases on older sites).

Fix mapping:

  • Temporarily revert to defaults for privacy/protection settings, then re-tighten one toggle at a time.
  • Keep ETP on Standard and use per-site exceptions for problem domains.
  • Review DNS/VPN/ad-block layers (one at a time). Stacked blockers can break session endpoints.

The trick is to change one variable, test one site, then keep the smallest possible relaxation.

Final thoughts

Session problems look random, but they’re usually consistent once you identify the pattern: blocking/tracking protection, corrupted site data, or Android killing the app in the background.

If none of the mappings match, note whether it’s one site or many, and whether it changes with VPN/Private tabs—those two clues usually point straight to the cause.