Dropbox won't sync particular database?

I used to use Dropbox as a sync, but disabled it recently. I decided to re-enable it, but using a different store name, yesterday. Everything seems to have gone ok, and DT is definitely creating files in that Dropbox folder. However, my main database refuses to sync with “Not yet synchronized, upload database”.

Screen Shot 2021-09-01 at 1.01.44 PM

This is after giving it about 22 hours or so. Nothing in the logs. Any ideas?

The spinner shows it’s working on something.
Hold the Option key and choose Help > Report bug to start a support ticket.

Done. Note, the spinner beside Filing Cabinet is now gone:

Screen Shot 2021-09-01 at 2.01.57 PM

Not sure, but DT syncs one by one each sync remote database. Once lower one finished, will sync new one.