I've tested just the standard plugin command of Play video and again, either waiting for it to finish or ending it early has the same issue.

I've also tried a version with the play video function and then adding a conditional branch to it that's set to "If: Button [OK] is being pressed" and then the plugin command for End video and again that works, but then it's never able to play that second video a second time.

Have also messed with the Auto Reserve Video being off and on and doesn't seem to make a difference.
EDIT: I have also tried making a completely fresh new game project and still got the same bug