Problem:

After playing some videos with the 21:9 aspect ratio (with black borders) for 1 to 2 hours, the user returns to the home screen and finds that a black line is displayed at the boundary between the video content and black border.

Solution:

This issue occurs with specific video sources, and only in this scenario. About 20 minutes after the playback stops, the horizontal line automatically disappears, which does not affect the normal use of HUAWEI Vision or the normal playback of other videos.