Are you installing FUSE-T with home brew? Else, it should be pretty obvious which version you installed manually. Recommend uninstalling FUSE-T then reinstalling the latest version if you aren’t sure which version you have. There’s a lot of known bugs in the older FUSE-T versions…you probably don’t want to be running an old version.
Edit. Looks like others are having the same issue with the latest FUSE-T.
When saving changes to .docx file multiple folders created, file lost
Edit 2: I can reproduce this with Word. Didn’t happen with Excel.