We've seen this happen when the user's files were saved to a network drive and that network drive had special configurations. Does that sound similar to your setup? And if so, could you reach out to your IT team or the server admin(s) to see if they could check for any settings on the server to see what the cause may be?
As a test for this, could you also try creating a new file and then saving it to a local path on your computer, e.g. your Desktop, to see if the issue occurs for that file too?