Xiaomi
Change App Lock Settings auf Xiaomi
Turning on App lock only sets the basic protection. Several related switches decide how strict that protection feels day to day, and they live in a separate menu from the initial lock setup.
Open Settings ➔ Apps ➔ App lock ➔ Settings to reach this menu, then Enable or disable the desired function for each option.
What each switch controls
Hide notification content stops message text and sender names from appearing on the lock screen or in the notification shade for locked apps. Without it, a chat app can stay locked while its previews still reveal private content.
Unlock all apps at once removes the need to unlock every protected app separately during the same session. This is useful if you lock several apps but do not want repeated prompts.
Receive recommendations (advertising) lets MIUI suggest additional apps worth locking, based on usage patterns. Turning it off stops these suggestions without affecting the apps already locked.
Disable app lock removes protection entirely and clears the settings for locked apps. Use it only if you no longer need per-app protection, since re-enabling it means setting up locked apps again.
If an app still asks for unlock every time despite Unlock all apps at once being on, check whether that app was re-added to the lock list after a system update.