Maybe Airone and AZ do not use the same IT systems, and the AZ PNR does not work on Airone and viceversa. If AZ bookings show up on checkmytrip.com, you can try logging in there and see whether the Airone PNR is reported there.

Or the easiest would be to just call AZ and either ask for the Airone PNR or ask them to select the seat for you.