Got an XAMMP / Moodle enviorement and it took me almost one day of work to figure out that nothing is wrong with my mp4 / html way of embedding videos, but that all iPads we use that are running iOS 10 are having this very problem that they won't run those videos.
I googled for a while and finally found this interesting post where I can not answer to because of not enough reputation:
HTML5 video/audio player on mobile Safari (iOS 7 & iOS 10) excludes cookies
They are talking about 'For iOS10, if you respond with a 403 forbidden, AppleCoreMedia will somehow try again but this time with the missing cookies' and everyone seems to completly understood what has to be done.
I don't and I would be super thankful if anyone can explain to me what I need to do in order to make those videos run again.
Thank you very much!