Touch Bar Video Controls in Safari

Hiya,

I have just bought an M1 Macbook Pro running Big Sur (v11.4). I have been using Safari (Version 14.1.1) for general web browsing and have noticed the video controls that appear when, for example, a YouTube tab is opened seem to vary for no reason. Sometimes it is just a play/pause button and a 15s skip; sometimes it is a full tracking bar with play/pause button on the side; sometimes it is a full tracking bar with a search button on the side.

I suspect it's doing it with other media players but it's been most noticeable on YouTube.

It's making it difficult to get used to using the control because I can't predict what's going to come up, and it's annoying when the play/pause button disappears as this is the most useful one.

I have attached images of the three sets of controls - I got these by switching between YouTube videos and refreshing the pages. They all came up one after the other. It doesn't matter whether an ad plays at the beginning or not.

Is this a known issue or particular to my Safari install?