Been like this from iOS 16.4 beta 1 through official. Cannot find a fix. Searched the web but it seems few people use beta so nobody was talking about it. My suggestion would be subscribe to Netflix or stop watching p***n on your phone and use your laptop ;)

There used to be a bug far back on iOS i-forgot-which where videos were all audio no video and the fix was to adjust the experimental features in Safari settings. I tried tweaking them a bit but no dice. You can try, but I don’t think it will work for this one.