I always laugh when someone leaves due to some made up reason.
This sucks though, and the thread is on 2200+ replies, filled with people experiencing this. Definately legit.
I have also noticed a distinct lack of technical polish this expac - lots of random DCs, inexplicable locks for 6-12 seconds. Randomly will start stuterring (like you described, only it goes away after 1 pull)… odd add-ons clashes, even fully up-to-date ones making it so I can’t click links in chat or a variety of other odd effects.
Heck, sometimes even my graphics go haywire and everything gets these lines of weird rainbow colors that I have to refresh UI to fix.
Fortunately, nothing that renders the experience unplayable. That really sucks OP.