https://bugs.winehq.org/show_bug.cgi?id=49392
--- Comment #4 from Louis Lenders xerox.xerox2000x@gmail.com --- (In reply to Louis Lenders from comment #3)
I`ll do some more testing and update or resolve this bugreport later
Ok, video`s do play when otter browser installed in "real" windows (10)
So probably wine-bug after all.