This issue has been resolved in the latest system software version. Please check system update notifications and update your device to the newest firmware version promptly.
If the issue persists after updating, please try the following troubleshooting steps:
1. Restart the device and reopen the short videos.
2. Check whether automatic brightness is enabled and recalibrate ambient light detection by adjusting brightness manually once.
3. Clear the cache of the related application.
4. If the problem continues, please contact the after-sales service center for further assistance.