Activities Freeze Shortly After Starting

Either get a blue bar that never finishes and requires a restart to end MSFS, or shortly after take off, stutters and eventually freezes, restart required.
Almost all of the time, I can fly from the World Map (same locations) without issue.
For example - FS Academy Voyager - I can fly mission 6 (NZ), but nothing else, VFR I can fly 1 to 8 and 12 but not 9,10 and 11. I have tried removing community folder, resetting to defaults, safe mode, same result. I haven’t started from scratch with fresh OS and game install, though that is on the cards if I can’t find another solution. Any suggestions welcomed!