As @MEL_Traveller mentions if you've added or made other flight changes that used to result in a new e-Ticket being issued with a new number.
@NoobTraveller try the Finnair website that used to show all the ticket numbers issued to that PNR, use the drop down arrow on the right circled in red. You can email the latest version to yourself by pressing E-ticket Receipt.

@NoobTraveller try the Finnair website that used to show all the ticket numbers issued to that PNR, use the drop down arrow on the right circled in red. You can email the latest version to yourself by pressing E-ticket Receipt.
