I carefully followed the steps, Global Inbox is on, but to no avail. It’s not loading the contents from de Dropbox sync store.
Are you using DEVONthink Personal?
What’s in the Dropbox syncStore - ie. what data do you expect to be in there?
Did you use the Dropbox or the Local Sync Store option ?
I am having the same problem with Devonthink Pro Office and DTTG.
What is reported in DEVONthink’s Window > Log ?