Why does the Xiaomi Watch S4 still go black even with the Always-on display feature enabled?

Even with the Always-on display feature enabled, the Xiaomi Watch S4 can still go black in certain situations to conserve battery and optimize performance. It is designed to manage its power usage efficiently.
The screen can turn off automatically in the following scenarios:
1. If the watch detects that it has been removed from the wrist for more than 5 minutes, it will automatically go black to reduce power consumption caused by the screen staying on;
2. If the watch detects that you have been inactive for 15 minutes (e.g., during sleep), it will automatically disable the display to save power.