I am seeing this too, and I am not running AMD. It started with 7.15 and my antialiasing seems to work when I log in and stop when I zone, and I'm getting the same stuttering that you described. I've tried resetting my graphics settings, rebooting, forcing AA through the NVidia drivers, and repairing the game. Nothing seems to help. My next step is to roll back the driver and see if that makes any difference. The game is choppy now, too.

Here's my hardware setup:
Intel i9-14900KF 3.2 GHZ
TEAM T-FORCE DELTA 32GB DDR5-6000MHZ
ASUS Z790 GAMING WIFI7 DDR5 ATX W/ 1GBT LAN, 4 PCIE X
NVIDIA GEFORCE RTX 4070 TI SUPER 16GB GDDR6X
4K LG Monitor

I really should not be seeing stuttering or losing antialiasing on this machine, and neither should you! I think something got borked with the last update.