For the record, this has happened to me upgrading myself before, but this case was much more annoying because I wasn't there.

Last night, a friend of mine showed me a booking he made on United. There were two segments, marketed and operated by AC, in Flex.

I added him as my upgrade nominee. Then I waitlisted him on today's flight, and confirmed an upgrade on a future flight.

I tell him to go check at the gate (the flight was massively delayed, so it was well after "departure" time), and they tell him he's not on the list.

Even with my Aeroplan number in hand, the system was spitting out stupid errors like "previous upgrade exists from another eUpgrade account".

So, while sitting 2254 miles away, I call the central concierge, and explain the issue, and talk about the experience I've had in the past.

He confirmed it was the same situation. In the reservation, he was waitlisted. In DCS, he was not. At the gate, they process the DCS list.

Apparently, when the upgrade request went in, it added a segment to the PNR in R class, coded as HL (a "weird" waitlisted status). His original segment was in Flex (Q?) coded as HK (confirmed). Apparently the concierge would have expected HS (a regular waitlisted status?).

I don't know how he fixed it, but he got my friend on the DCS list. Luckily, there were still 3 open seats in J.

But how does this crap happen? Like literally, if the upgrade list does not transfer to DCS, then what the heck is the point of anything? I'm pretty annoyed right now. But not surprised.