BUG: Video playback is slow

I've attached a text doc that shows an example of the coding within the ebook. There are a lot of these files in each book. So we break them up into different chapters and usually makes each guide have about 4-5 books. So for example Book 1 might have 6-7 chapters with 1 video in them each. This in the past has reduced the load time. However for now we are running into an issue for some reason.