I have been finding an issue with videos in the over and under style. (for example this video: https://www.sexlikereal.com/virtualreality/scene/id/4335-under_my_skirt_with_katy_gold)
If the video has been downloaded in the app and you go to play it there is clearly something wrong. After mucking about I found that if you look at the video through the video player (rather than downloads) you can enable Direct Show which seems to fix the issue. Annoyingly you cannot do this in the downloads section.
I hope this makes sense.