Mobile browser YouTube keeps changing settings

So I have ad blocking extensions enabled among a list of other privacy related ones. So I can watch YouTube without ads on my browser.

I've noticed that YouTube keeps changing settings on my browser. It'll disable autoplay. So I can't have a video playing in the background without it open.

And to watch the movies available with ads, it says I need to do it in the app, but I switch to the desktop setting and it's started switching the setting to block drm controlled content.

How can I stop YouTube from changing my settings without my permission or consent? Is there a setting in Firefox to stop this? I assume they're doing something with cookies.