✳ SUBTITLE DIAGNOSE
Diagnose: uploaded subtitles are out of sync or drift
Dynamic diagnostic state for this problem. Choose a file to run the diagnostic tree; the page rerenders with ranked causes and recommended fixes.
Direct answer
Uploaded SRT/VTT subtitles drift when the timestamps don't match the actual frame timing of the file the player is using. Re-time the captions against the player file (not against the original cut) and re-upload; many editors let you shift the subtitle track by a fixed offset.
Run the diagnostic tree
The tree combines this problem's static cause ranking with the values the diagnostic engine reads from your file.