The situation is that some old videos are experiencing issues. After asking Cat4 to investigate, the cause was found to be that their segments are corrupted on storage, resulting in videos that cannot be viewed. Currently, the 480p video profile is still operational so I will temporarily convert all old videos to 480 quality.
The conversion process may take up to 3 days for all old videos.
The affected old videos are those uploaded from June 2024 and earlier. Some videos may still function normally!

Hopefully 1080 will come back to the old videos!