Happens to me in Palm Beach, FL heading to ATL connecting to CPH. The PBI lounge scans the boarding card and then want to input my SKG number which really doesn’t do anything. I have Amex Platinum that would work in the Delta lounge as well but I want to see if they can figure it out. I have done it 3 times. Once they figured it out and brought me my boarding card about 10 minutes later. The other 2 times I really think they gave up because it says Sky Team Elite Plus on the boarding card.