itamex, same experience for me: I can't choose any preferred seat on the AM app as a DL Platinum. The app recognizes my status and lets me pick preferred seats that are "complimentary thanks to your medallion status" but the choice never sticks and the seat reverts back to the one i had previously. I have to call to get the seats I want and it's always an ordeal.

However, last time I flew AM to the US, I forgot to call for a seat, and I realized I could pick a preferred seat at check in, and then the choice would stick. I guess the routes I travel on have a lot of basic economy travelers so there are a lot of available seats to pick from when OLCI opens, and at least from that time, the Medallion seat selection works - so I thought I'd share that

A.