Accessibility question: I have a PowerPoint presentation. It includes videos. Those videos have captions. I worked hard to make those captions correct (they are very mathy at times). But I cannot get the captions to play automatically when the videos start. Every single time I have to turn them on.

Implied question that I ran out of characters to add: Is there any way at all to have the captions on by default on all of my videos? (Why isn't this just the default all the time?!)

How were the subtitles made? Do they exist as a separate file (e.g. as a .srt file) or is it all within PowerPoint?