I agree: I call BS by the airline, and further, I suspect the UAL ground manager was 45 year old non-male.....I had a similar experience a few years ago....I arrive at the airport in plenty of time, no baggage to check proceed to the gate, still a hour before the flight, check in with the gate staff, assigned a seat, so I sit and wait, flight is called and I take my time, no rush as I have an assigned seat, however the gate agent, said sorry the plane is full....I could not believe what i heard and I had a court case at the destination, however the airline said f off take the next flight!!
“a hour before the flight, check in with the gate staff, assigned a seat, so I sit and wait, flight is called and I take my time, no rush as I have an assigned seat, however the gate agent, said sorry the plane is full”
On most airlines they are allowed to give away your seat if you aren’t ready to board 15 minutes before flight time. They usually close the door 10 min before but that’s 5 minutes when it is still open that they can give away your seat if you aren’t there, even if you have boarding pass