I had this issue the other week. I found via the AA mobile app, that you could try to enter the Qantas PNR and surname, get it to fail, and it'll take you to a different screen where you can enter the PNR or the ticket number. So, I copy-pasted the Qantas 081 ticket number into the box from the booking PDF, and it failed again... which I realised is because the box has a character limit and by copy-pasting, it had included the hyphen after '081' and lost a digit at the end (the character limit allows for only the exact number of, well, numbers in the ticket number)... so I pasted it again, took out the hyphen this time, and then went back and manually typed in the last digit of the ticket number (which I now could, without the hyphen hitting the character limit), and voila, it worked. Noted down the AA PNR just in case, but it then remained in my AA app.