When MSFS 2020 loses all its settings, it may be that you have GForceExperience and the option to optimize compatible games is activated.
Also when starting up, if it asks you to configure everything again, it may not sync with the cloud and for some reason on your PC you may not find data saved in this path:
C:\Users\YourUser\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\SystemAppData\wgs\000901F3B8C2046D_00000000000000000000000069F80140