"Upload Failed: We're sorry this didn't work"

I recently migrated all of my Box folders from a university Box account to a personal Box account at the Business level. Folders are shared with maybe 30-ish other people. I use Box Drive on my Mac laptop. Since the migration, I can save new files and have them sync, but every time I try to update an existing file (ppt, word, excel), I get an error message saying “Upload failed: We’re sorry this didn’t work. Try saving again later, and if that doesn’t work, click Save a Copy” with a button for “Save a Copy”. The updates will save locally, so I don’t lose them for now, but they are not synced with Box for others. It doesn’t look like they are saved (i.e. the date last changed is not the most recent date of edits), but when I open the file, the newer version does appear, likely because a temporary file is stored. This same issue is happening with at least two other users of my Box business account.  How do I fix this, without losing all of the temporary files that I’ve created when files haven’t synced/saved properly? Thanks!