With drivers newer than 577.00, there will be CTDs if MSFS is running in DX11 - even without the Nvidia app.
If you want to use the latest Nvidia drivers starting from version 580.88, DX12 must be selected in MSFS 2020 settings.
If you use driver version 577.00 or older and want to play DX11 in MSFS 2020, the Nvidia app should not be installed.