Same problem here, before the update I had 30-50 on air and around 20-30 on ground, after the update I have 10-25 on ground, is amazing how bad optimized this game is.
I run almost everything on ultra, but the funny thing is that even if I put everything on Low end, the fps are the SAME, turned photogrammetry off and the SAME fps.
I believe I have a good machine and this is the only game my computer seems to struggle with.
i9-9900k-3080Ti-32gig ram-game on Nvme. 1440 165Hz monitor.
I’m tempted to re-install windows but if there’s no guarantee will be fixed I’m not sure.