Safari not supporting Full Screen Option for play a video links.

When using a iPhone or iPad to view a video from a Google Drive link in full screen it does not allow you to do so. The message that appears is “your browser does not support full screen”. But all other videos from YouTube etc… will play fine in full screen on my IPad and IPhone. This seems to be a intermittent problem. Safari will allow the full screen at times, then at other times it will not. A Samsung Galaxy user had no problem viewing the video in full screen when I sent it to them. Two IPhone users I sent it to could not play it in full screen. They received the same message.

So is this a Safari problem or a Google Drive problem? Google blames Safari in a email response I received.

I am using IOS 15.5 on both my iPhone and IPad.

I was in a Chat with Apple and they were successful in recreating the same issue themselves.

What exactly is going on?