Microsoft files opening view only

I have users with an intermittent issue; they save a file to box drive, then sometimes, when they re-open the file, it is view-only, they click enable editing, and then are prompted to save the file, which defaults to a filename that would be a duplicate except the spaces are %20, they can't save because the file is open, so they save to their desktop and stop using box, effectively. I thought it was MS autosave, so I had them turn that office in the options for each MS program, but the issue persists.