Booked an SAS flight CPH-BOS via Delta.com but could not reserve seats in the DL app. Told me to enter the PNR at flysas.com but I just kept getting kicked out. Anyone know the trick to doing so? Thought there might be a separate PNR for the SAS flight (flight to EU is on DL metal), but I wasn't going to bother calling in today without checking around here first. Any Intel appreciated. Thank you.

Also, FWIW, I booked a separate leg intra EU direct at flysas.com and was happy to see my Gold status got me free preferred seats for my party of 5. In the checkout process the seats showed up with a cost attached, but the subtotal listed my seat as free, and when I checked out the system removed all seat charges (I checked, the seat reservations were preserved in the booking). Nice unexpected 100EUR benefit.