I have also been suffering from these ctd the last 2 days or so.
Sometimes the faulting module for me is ntdll.dll but sometimes it is also flightsimulator.exe.
The coincidence of these sudden ctd make me think that the flightsimulator.exe crashing is part of the same issue and not separate to the ntdll.dll issue.
There are quite a few reports in the https://forums.flightsimulator.com/t/constant-ctd-every-flight-now-ntdll-dll/537543/ thread for the flightsimulator.exe being the crashing module so I would still report your findings in that thread.
The most common module appears to be ntdll.dll but if the crashes appeared out of nowhere in the last 48 hours or so and it is flightsimulator.exe as the faulting module, then there is a good chance it is a symptom of the same (as yet unidentified) underlying issue.