I had similar issues. Dont do a full reinstall until you’ve exhausted all the possible causes.
e.g.: Msfs 2020 won't launch
This guy had his clock set to a different timezone. Imagine that.
Now, if you search a little bit, you will stumble upon a great variety of little tricks that can help you diagnose your problem and fix it. This forum, in conjunction with good old Google can do the work.
I’d start by logging off and then back online on Xbox Gaming Services - and also Microsoft store (Maybe Stea, if you’re a Steam version).
But again, this is just the tip of the iceberg. I still suffer from CTDs once in a while.
Good luck