Hello! A client I'm working for is having a "drift issue" with an MP4 we recorded. The audio consistently gets more desynced the longer the video goes. I don't have much info about when they recorded it, except for the recording itself. I tried replicating the issue yesterday, but didn't seem to find any similar issues, though I'm worried the box wasn't as taxed in my testing as it was for this record.

Does anyone have any suggestions as far as reasons this could be an issue, and how I could go about debugging it? What information would be helpful to track this down going forward?

Thanks,
-Elliot