In Iphone Authenticator not working properly when we switch app for codes .

The behavior described typically happens when the Authenticator prompt is waiting for approval while the app is locked, notifications are misconfigured, or the sign-in flow is interrupted when switching apps. Use these steps to break the loop and complete sign-in more reliably on iPhone:

1. Update and check basic Authenticator settings
   1. Open Authenticator on the iPhone.
   2. Ensure it is updated to the latest version. If the app is more than 12 months old, it is not supported. In Authenticator go to Settings and make sure App updates is turned on.
   3. In Settings:
      • Turn Turn off battery optimization (or any power-saving setting that may pause the app) on for better sync performance.
      • Go to Notification Settings and ensure Show notifications is turned on.
   4. On iOS system settings, verify the device Date & time are correct and set automatically.
2. Fix notification and “stuck number screen” issues When switching from Outlook (or browser) to Authenticator during sign-in, the app may show only the number-matching screen and not let navigation back if:
   • The app is locked.
   • Notifications are silent or blocked.
   Do the following:
   1. Make sure Authenticator is unlocked before starting the sign-in flow.
   2. In iOS Settings → Notifications → Authenticator, enable:
      • Allow Notifications
      • Alerts on Lock Screen, Notification Center, and Banners
      • Sounds/Vibration if needed
   3. Ensure the phone is not in Do Not Disturb/Focus mode, which can interfere with prompts.
   4. If the number screen is stuck, force-close Authenticator and Outlook, then reopen Outlook and restart the sign-in. After that, switch to Authenticator only when the prompt is expected and the app is already unlocked.
3. Check for “Authentication did not complete” conditions If the sign-in keeps failing after switching apps, verify:
   1. Authenticator is unlocked.
   2. Notifications are not silent or disabled.
   3. The app is updated to the latest version.
   4. The iPhone has a working internet connection (try switching between Wi‑Fi and mobile data).
   5. Device date and time are correct.
4. Use an alternative verification method temporarily If the loop continues and Outlook sign-in cannot be completed with number matching:
   1. On the sign-in screen, choose I can’t use my Microsoft Authenticator app right now or similar.
   2. Use an available alternative method (SMS, email, or verification code) if configured.
   3. Once signed in, review security info and, if needed, remove and re-add the Authenticator registration so the next setup is clean.
5. If still locked out of Outlook
   • For work/school accounts, contact the organization’s admin and ask them to require re-register multifactor authentication for the account in Microsoft Entra so Authenticator can be set up again cleanly.
   • If already in Outlook on another device, use that session to review and adjust security info and MFA methods.

These steps address the known causes where authentication does not complete or notifications and prompts do not behave correctly when switching to Authenticator on mobile.

References:

• Troubleshoot problems with Microsoft Authenticator
• Authentication did not complete