I tried and tried but it just doesn't work

I am using WordPress 4.4 with the S2Member framework.

Sometimes videos play, sometimes they don’t.

Playlists do not work at all. All I get is a video loading with <prev and next> links under it. Audio starts, but no video. Clicking video changes it to a black screen.

I was under the impression the videos would all be under the main video and replace the main video.

I have to load 20+ videos all on one page, then wait for them all to load before the first video will even work.

I’ve tried and tried over the years but this has just never worked correctly for me. :/