Another problem that happened, my simulator crashed when I was downloading some of the free content. My download became stuck, (a 'World Update) and I believe I had crashes following this and the download would get close to finishing and stalled every time. The download was corrupted. I used the content manager to remove the scenery update that I was downloading and then I downloaded afresh and this solved my problem.
Could try this and navigate to C:/Program Files/WindowsApps/ Microsoft.FlightSimulator_1.18.13.0_x64__8wekyb3d8bbwe Right click the ‘Flight Simulator.exe’ opening the properties of the executable. Open the ‘Compatibility tab’ and enable, ‘Disable full screen optimisations’ You could also enable, ‘Run as administrator’. I discovered last year that I had multiple registry entries for this folder, Microsoft.FlightSimulator_1.18.13.0_x64__8wekyb3d8bbwe, (the name of this folder changes with each update and so it was called something else. Using CCleaner I deleted the old remaining registry entries for the old folder making sure to keep the current new folder. You could try that to see if you have multiple entries in your registry.
I am no expert in this matter however, there is no harm in checking.
You could also, (if not done so already assuming you can get the the ‘Options’ page in MSFS) re-set all your graphics settings to default in MSFS.
Using the Nvidia Settings, set all of these settings to default.
Try starting flight from a new location and turn off ‘Live weather’ to see if that makes a difference.
Disable ‘Live traffic’ and see if that helps!
I wonder if there is simply something that needs changing in the ‘flightsim.ini’ file. I cannot remember where it is located. Perhaps there is some duplicate settings in there?
Perhaps you could also try cleaning out any cached scenery from within the simulator.
If you are using overlays from Nvidia Ge-Force Experience, try disabling them! I am using the ‘skinny driver’ which I installed today which is working great. See below and follow the link from there.
New Nvidia Drivers: 471.41 WHQL 19/July/21 - #677 by CptEvillian
I want to try and help, alas this is all I can think of at the moment.
BRGDS. And good luck Charles