Thanks. So, the upgrade for my companion and I cleared overnight (as shown in the reservation system). However, I'm unable to select seats in F. I can see the seatmap and click on a seat but it doesn't stick.

I called the 1P number to try to ask to be "offloaded" and then assigned seats as per the advice in the thread talking about known glitches about getting an upgrade through the reservation system after you've already checked in. But the rep said the flight is already controlled by the airport (It's 5AM and the flight isn't until a little after 1PM). Oddly, the mobile app still shows both of us as on the upgrade list. I guess I'll need to figure it out the airport. Any advice? Thanks