This is an issue with any ticket booked via CO on UA metal, even for a 1K like myself using only my UA MP # in the reservation. I have no clue if its a CO issue or a UA issue, but its a pain. I too have to call for a change in seats, and even though I get the 1K line I have better things to do with my time.

Point being is that you CO guys aren't alone in your frustration.