I've had this same problem ever since I got back into the game right as endwalker came out. I have always played this game with controller and never had these issues before, but none of the solutions that I've found here, on Reddit, or online have worked so far. It's so frustrating to be doing something in combat and then my character just stops randomly for 2 seconds. If anyone finds an actual solution, I hope it'll work for me as well. I suppose I should also mention that I play using the Windows launcher, not from Steam