For our upcoming trip I had to make separate reservations for the 3 of us as we're coming from different cities and meeting up at a connecting flight. For the common legs I was sure to select seats so we're all seated together. I have confirmation emails back from United showing seat assignments. A few days ago I decided to double check our reservations and make sure everythings good. On two of our reservations seats were fine but mine showed no seat selection made. Luckily the seat next to my family was still available so I selected it, got a new email and all is good....maybe. Today I checked and once again my reservation shows no seat assignment. I once again selected it but what could be happening? I called United and they have no idea why it keeps bumping me from my seat.