Same for Formula HiTech Gen2 M3 low downforce version.
I think the AI do not use the low downforce setup. It is the same on Monza.
Something is wrong with the FFB Low Downforce Version of the Car
Track & Layout Used: Monza 1991, Hockenheim 1988 Car Used: McLaren MP4/8 Low Downforce Version Applicable Settings: Practice Report: Low Downforce...
Reset to default setup and everything in fine.
I had the same problems as you with 1.48, no AA at all in fullscreen-mode. 1.49 all is fine, no special settings, only game mode on.
Since AMS 1.49 everything is runing fine for me. AA working well (no NVIDIA Inspector needed) in fullscreen-mode. Running NVIDIA GTX970...
Separate names with a comma.