Mine posted about a week later.

Weird thing happened at check-in that made me wonder if it would work, though: I instructed my TA to put my CO number on the flights. But at the check-in kiosk, the screen showed my UA number!

(I'm sure I had used that on a DL flight at some time in the past, but not for over a year, for sure!)

Anyway, the boarding pass printed with the correct CO number, and everything processed properly.