What to do if the Xiaomi Watch S3 has a black screen after factory reset and cannot be turned on?

This problem is known. This problem has been optimized in the latest software version. Please press and hold the watch power button (down button) for 12 seconds to force restart. After the watch restarts and the screen lights up normally, open the [Mi Fitness] App, and in the App tap [Check for updates] on the device interface and follow the reminder instructions to update to the latest software version.