Opening a fixed mini player automatically is a feature offered by the website and is created via JavaScript if the main player is scrolled out of view. A lot of websites now have a fixed (pop-up) mini player in one the corners once you start plying a video that stays visible if you scroll the page. This website mini player shouldn't be confused with the Firefox PiP (picture-in-picture) feature (you likely see the Firefox PiP icon if you hover the mini player).

Thanks for taking the time to answer but you didn't say how to disable it. furthermore, I don't think this applies to my picture-in picture problem. After a thorough internet search I discovered that your answer applied almost exclusively to YouTube users - not other videos. Also I never had this problem with YouTube so your answer cannot apply to me. But thanks anyway.

Can you post a link to a publicly accessible page (i.e. no authentication or signing on required)?

OK, here's a video from a news story I was watching on Firefox. https://nypost.com/2021/07/20/watch-as-jeff-bezos-blasts-off-into-space-with-blue-origin/

This website mini player shouldn't be confused with the Firefox PiP (picture-in-picture) feature.

Opening a fixed mini player automatically is a feature offered by this website in every browser and is created via JavaScript if the main player is scrolled out of view.

A lot of websites now have a fixed (pop-up) mini player in one the corners once you start plying a video that stays visible if you scroll the page.

OK, assuming you're right and this applies to me, How do I stop it permanently. I absolutely hate it!