Full screen video on iPhone popup

I’ve got a popup that plays a video. When playing on a laptop or iPad the full screen button will do just that. However when playing on an iPhone it has no effect - either running in the preview or from the host.


EDIT: device photo

Catalina 10.15.7
iOS 14.1

I just tried and it works for me. Would you send the project file over so we can test the exact setup?

Document sent! Thanks!