After I got blocked from watching further videos, I disabled uBlock on Firefox, clicked any video and then enabled uBlock again. For some reason neither the blocking nor the pop-ups came back after reloading or since.
I see loads of posts that ad blockers stopped working on youtube. However, I still have no ads there. I'm running vivaldi with ublock on Linux and Vivaldi with minminguard on Android (EU based).
Google/YouTube never rolled out new features to all users at once, especially for new controversial features. They always do staged rollout (e.g. 1% of users, then 5%, then 10%, etc), often geographically limited too. That way they can gauge the potential impact of the new features before fully deploying them (e.g. whether the new features would actually increase their projected revenue or actually decreasing it).
That would explain a lot. We'll see how this develops. For me it would be no big loss when adblock detectoon starts to work here. Loads of spare time to get back. ;) (no ads or no content, as I refuse to watch ads)
There's 3 reasons why you might see this AdBlock nonsense:
YouTube changed something and the filter lists need a bit of time for volunteers to update them
Your auto update of filter lists did not pull the above update yet
Some other addon/privacy feature interferes with ublock or triggers the adblock detection themselves
If you didn't run into any of these yet, you'll have no problems. Also sometimes you might have one of the above problems, but the adblock detection feature may not have been rolled out to your region/account yet, so you're also fine.
Mine just started working out of nowhere. I went to YouTube on my chrome browser to find a video I wanted to watch so I can play in Firefox and it just played as normal 🤷🏾♂️