Why doesn't Huawei bracelet show the time, and there are four question marks?

When the bracelet is powered off and turned off for more than 2 days before recharging, a question mark icon will be displayed at the starting time position of the bracelet, or the time after the bracelet is turned off and restarted will be displayed as 0.

The cause of the problem:

After low-power shutdown, the clock power of low-power operation inside the equipment side has also been exhausted, and the time cannot be displayed normally after charging.

Solution:

After the bracelet is connected to Huawei Health App for data synchronization, the time display on the bracelet can return to normal.