Microsoft Defender keep turning off on my Galaxy phone

Configure the Galaxy’s battery controls to leave Microsoft Defender unrestricted and restore its Accessibility permission; intermittent internet access may limit online services, but it is not the documented reason that web protection switches off.

Samsung Galaxy settings

For Samsung devices running Android 13, Microsoft documents this sequence; menu names may vary slightly on other Galaxy/Android versions:^1^

1. Long-press Microsoft Defender → App info.
2. Turn off Remove permissions if app is unused.
3. Select App battery usage → Unrestricted.
4. Open Settings → Battery and device care → Battery → More battery settings.
5. Turn off Adaptive battery.
6. Return to Battery → Background usage limits → Never sleeping apps.
7. Add Microsoft Defender.
8. Open Microsoft Defender and select the Device protection card or Web protection alert, then complete the prompts to turn protection back on.

Defender’s Android web protection needs to run in the background and use Android’s Accessibility Service. When Android stops the app to save power, it can revoke that permission and web protection turns off.^1^

If Defender requests Accessibility access again:

1. Open Settings → Accessibility → Installed apps.
2. Select Microsoft Defender.
3. Enable the service and approve the prompt.

Only one app at a time can hold the Accessibility permission Defender uses for web protection. Granting it to another app can turn Defender web protection off.^2^

Distinguish connectivity from permission loss

After applying the settings:

1. Confirm Defender reports Web protection: On.
2. Disconnect from Wi-Fi and mobile data for a short test.
3. Reopen Defender:
   • If protection still shows On, the earlier shutdown was related to background or permission management.
   • If it shows Off, check whether Defender’s Accessibility permission was removed or the app returned to a sleeping-app list.
4. Reconnect before expecting cloud-dependent checks or updates. Microsoft notes that internet access may be required for some Defender services, but this is separate from Android disabling the background protection service.^3^

If the permission remains enabled and Defender is listed under Never sleeping apps, update Defender from Google Play and install pending Galaxy system updates. If it still turns off, record the Galaxy model, Android/One UI version, and whether Accessibility changed to Off; those details distinguish an app failure from Samsung power management.

References

1. Web protection keeps turning off on my Android device | Microsoft Support
2. [Android](https://support.microsoft.com/defender/installing-microsoft-defender)
3. Microsoft Defender for Endpoint on Android application license terms