VH-JQX Airbus A320-232 of QantasLink (Network Aviation), named ‘Wreath Flower’, at Perth Airport, Western Australia – 17 May 2024. Boarding the aircraft at 10:35am on bay 17, Terminal 3 for flight QF1830 to Karratha, which was scheduled to depart at 10:45am. Sat at seat 27A (3rd row from back left side, 3rd and 4th window from the back). The aircraft pushed back at 10:55am and started engines, but did not taxy out. After a few minutes, the pilot announced there was a technical issue with number 2 engine they were trying to resolved. This was unsuccessful and they said we would taxy back to bay 17 and get an aircraft engineer to check it. We went back to bay 17 at 11:04am. The engineer checked for some time, then decided it was a complex issue, and around 11:35am, we were asked to disembark and wait in the departure lounge and we would use a spare aircraft. I waited at gate 17A, as our flight was departing from bay 22. Boarded VH-VQR for the flight to Karratha. It VH-JQX later departed to Karratha at 1:54pm as QF1831.