This is what I recognize. Then MS updated Windows to solve this issue. When I installed that update, the issue started with me. Whenever I tried to start MSFS it redirected me to the store. And in the store there was nothing to do. I solved it by resetting / repairing gaming services. I had to uninstall / reinstall it a week or so earlier to get the last update.
I think your reinstall might have come when MS was sorting all this out (and seriously, it’s a mess… this whole business with GamingServices / XBox and Windows mix… I think they’re still trying to figure it out themselves).
So by trying to fix it, you might by now have messed it up so badly that a Windows reinstall is the only way out. Without blaming you mind you. This is on MS and their messy store. I hope they improve this in Windows 11.
So basically I’m saying that a Windows reinstall this time might stick. Still not advocating it, but getting help from here will be near to impossible. I think no one from a distance can just diagnose this and fix it. It seems you already tried everything yourself anyway.