Those browsers are preferring WebM VP8/VP9. (which do not work on Safari and iOS)
Is there a way to convert uploaded files on the fly and offer both to the browsers?
Thanks @texnixe, wow ffmpeg. Blast from the past.
For clients, I like to make things as easy as possible.
I will look into installing ffmpeg with command-lines.
I was hoping there would be a plugin by now, but vidembed by Hash&Salt @jimbobrjames only support one format too.