Honestly, I'm having the same issue. Ever since the early access on Endwalker, I get dramatic frame rate drops from 60 to 16, just by running in an area at Ala Mhigo or Kugane even. It's awful in dungeon runs, esp. the last MSQ dungeon and in trials.

I updated my graphics driver, checked all my graphic settings, nothing's changed. My benchmark was rating was "Fairly High," and after EW's early access, the benchmark now runs on "Slightly Low."

I have a GTX 1080 Max-Q GPU, and I can't even run the game on standard settings without having dramatic frame rate drops. Game mostly runs on 30 FPS and drops to 18 FPS. It's outrageous.

I've done everything I possibly could on my end (running laptop on high performance, emptying out the hard drive, tweeking the graphics settings more, etc.) all to no avail. I don't have Citrix, as I know some people have said that was causing the problem. Seriously hoping this gets addressed soon. It's almost been a month, and it's getting harder and harder to play. I know I'm not the only one with this issue (there was a Reddit thread about this before, and there was no real solution found).