hi, on android you can invoke picture-in-picture mode by opening a video in fullscreen and then hitting the home-screen button.

Thanks but I don't use a home button in the latest version of Android. Ive selected to slide up the middle of the screen to emulate the home button and that just takes me to the desktop/home. Am I missing something

yes, the steps you're describing are exactly the same for me - it's important though to start these steps while the video is playing in firefox fullscreen. i end up on the homescreen with the video playing in an overlay. another user comment at https://www.reddit.com/r/firefox/comments/bmxc6x/firefox_android_disable_pictureinpicture/en0qyeu also mentioned there may be a particular picture-in-picture permission needed for this to work, so you could check that in the system settings for the firefox app.

I couldn't see anything in the Firefox settings but in the Android settings under Firefox I could the permission for picture in picture is set to allowed. So no further ahead

Got it now

could you try if it is working correctly in firefox beta? (it is based on more modern technology which should replace the regular firefox on android in the foreseeable future):

https://play.google.com/store/apps/details?id=org.mozilla.firefox_beta

edit: never mind, i see that you could solve it now

Yes it is working fine in beta