It’s always existed, but it would be rare for fights to go over a few minutes. With the raid encounters being significantly longer, it’s more of an issue, and it’s an escalating issue.
I eventually had to turn off my recording, and lower my supersampling down to 0.8 or so (from 1.4), and was able to do what needed to be done for the fight, but the lag was still present and growing even then. (1080ti, i7, 32 gig ram, 1TB SSD, gigabit connection, etc)