I have an upcoming itin, with the outbound on p.s. flights (upgraded to C via RPU), and the return on a 2-class 777 (SFO-IAD). When I check on requesting an upgrade for the domestic 777 (to F), .bomb indicated there are no C upgrades available.

Is this just a display bug--since the outbound is in 3-class and the return is in 2-class--or is it something else I should be more concerned with as the UDU upgrade windows approach? E.g. is the system going to try an upgrade to C, which will never appear on the 2-class flight?