I have marked 4A and 4B for my Qantas 737 domestic flight from MEL-SYD, and completed online check in. However, Qantas mobile app is now showing the seats have been changed to 5E and 5F (though Qantas website and seatmap are still showing 4A and 4B). Called Qantas and was told they could see us sitting in 4A and 4B, not 5E and 5F? Anyone faced similar situation before? Is this a technical issue, or is someone from Qantas moving our seats?