So. As mentioned in another topic, I have changed two files in the game root folder: nvngx_dlss.dll and nvngx_dlssg.dll
Downloaded and copied new versions.
Download links: DLSS DLL, DLSSG DLL
RTX drivers are 531.79
Spec: i9900/RTX3090/32GBRAM
Graphics settings: DX12+DLSS/ULTRA preset
Resolution: 4K
Now I complete a full bush trip flight without any issues and errors.
Need additional tests from others.