Perma Alt-Tab Framerate

a few days ago, i updated my nvidia driver. since then, my framerate has gone from consistently low 90s, to now being in the 40-50 range.
i did a driver rollback, reinstalled the game, did everything you'd initially think for the troubleshooting, and it didnt change
after messing around with my settings for a while, i realized that the game seems to be retaining the frame rate that it normally has when tabbed out. i've looked online and seen years old forums posts of people having similar issues, where upon tabbing out, it retains the tabbed out framerate, but for me it starts as the low framerate from low boot
i already did a ticket with squenix support and they just ran me through hardware issues, which i'm not having
very important: none of my other games have framerate issues, it's just xiv, so it can't be hardware. it has to be some setting that got messed up when i updated that driver, but i have no idea what it could be