Huawei
Write System Settings: App Access auf Huawei
Write system settings is a special access permission on Huawei phones running EMUI. It lets an individual app change values that normally belong to the system, such as brightness curves, screen timeout or rotation behavior triggered by other apps.
By default only a small set of trusted apps get this access. If a third-party app that relies on adjusting these values stops working correctly, for example an auto-brightness tool or a display customizer, the permission is likely missing or was revoked after an update.
You manage this per app under special access, not in the general permission list, which is why it is easy to miss during troubleshooting. Turning the permission on only grants access to system settings values, it does not give the app control over personal data or other apps.
To check or change it, open Open the settings ➔ Tap on Apps ➔ Tap on Apps ➔ Open the menu ➔ Tap on Special access ➔ Tap on Write system settings ➔ Choose an app ➔ Activate or deactivate Write system settings.
If the app still misbehaves after enabling the permission, the issue usually sits elsewhere, for example in battery optimization or a missing notification access grant, and needs a separate fix.