I have zero ad-blocking in place normally for YT. My take on it so far is I think they've embedded certain functionality relevant to trying to defeat ad-blocking into the system which isn't working quite perfectly and sometimes [unintentionally] disrupting playback regardless of whether you are blocking ads or not, using Premium or not, etc. but it seems intermittent and for some reason not impacting people widely enough to result in complaints - possibly due to a lot of people only watching a relatively short amount of YT per day and just reloading the page the odd time it happens and thinking nothing of it - whereas I'm probably using YT for several hours a day even if that is just background stuff like music.