The exact question was:
I've added a section to my website that is a video library. This section lists all the videos from our YouTube channel. Each video has its own page where we are hosting the YouTube video with transcript and description of what the video is about.
My question, I created a separate video sitemap listing all the individual videos. Once I submitted the sitemap all 55 videos were indexed, but over time they are starting to get de-indexed (in increments of 5 or 10 at a time). Now only 9 videos are indexed. What would cause this? What can I do to troubleshoot why my videos are getting de-indexed? Everything in Search Console shows that my video sitemap has no errors, so I'm not sure what is causing this de-indexing.