Yep - all the same. As I note above, I seem to have narrowed down the exceptional behaviour to the global inbox - if I have used the Things 3 quick entry with autofill elsewhere in another database, or even in the inbox of another database, then it pulls in the last callback from that action.
If I have not yet used quickentry anywhere in DT3, then it won’t create any callback URL.
So I wonder if there’s an issue with the global inbox on my (home) mac. My work mac does not display the same behaviour.
What would happen if I simply deleted the Global inbox database in Finder and then reopened DT3 - would it create a new one?