you should can allways disable cloud-save in steam and it is usually persistent, also in case of msfs
You can check directly in Steam what currently is remote stored, see following post:
I also mention in that post, that you can have a look into steams-log file.
If we assume you have Steam installed in default C: location, then you searched the folder here
C:\Program Files (x86)\Steam\userdata\XXXX\1250410
( XXXX stands for you steam userid , 1250410 is the gameid for msfs )
?
Can you find the folders for all your other games ?
Be aware, that you delete in that way in the first step only the local replica of your steam cloud settings. Therefore these FAQ mentioned “disable cloud-save first”. Then, with starting of MSFS new files should be created and if you enable “cloud save” again, then Steam ask which files you want to use ( normaly ). If you find your folder, I recommend to backup these folder before you remove it.