Flying PDX-LAX-DFW-BTR this evening. Confirmed upgrade into first for both PDX-LAX (at T-27) and LAX-DFW (at T-77). I check in 24 hours in advance, get my BPs, all is normal. I wake up at 7:30am PST and notice my girlfriend still has her seat on LAX-DFW, but my seat assignment is zero'd out. I try to re-select the seats, but it isn't letting me. I call in, and the agent is confused and really isn't helpful. The chat agent says something glitched, which Twitter corroborates. Twitter also tells me to go see an agent in PDX as they will be able to help. I go to PDX early, and the agent is as confused as I am. The seat is still available, so nothing mechanical, but she said to see an agent in LAX. I also don't have a seat on the plane as of now, but I am #1 on the upgrade list (so I lost this first class seat, I guess). The PDX agent also said that the same thing happened to another passenger earlier in the day.

I'm about 35 minutes from landing into LAX, but very confused as to what has happened. Does anyone on here know what could be the issue or have any advice?

Thanks in advance!