Mod: please merge to a relevant thread if there is one on the DL forum. Thanks.

On the outbound of a recent international trip, I was unable to check in on either DL App or website. When I arrived at BWI check-in counter, an agent told me that she needed to verify the credit card (cc) for purchasing the ticket. She wanted to see the physical card. I found the bank statement on the bank’s App with the specific purchase. It was, however, not good enough for her. Also, the purchase price shown on DL computer did not match with what I originally paid (~$40 higher). The only solution was to call the Sky Priority line to swap out the original cc used for purchasing the ticket with a new credit card in my pocket because I did not bring the original cc.

So, my questions are 1) why did DL want me to present the physical card for purchasing the ticket before issuing me the boarding passes? 2) what triggered this strange requirement? perhaps, a) due to multiple changes to the ticket, b) due to its extremely low price of this Delta One ticket or c) due to DL slowly becoming a “third-world country” airline 🤪. Just kidding for the last one!

I talked to a few friends, who are/were DL frequent flyers. They have never had a similar experience as I had. It never happened to me on UA with more than 3 Million BIS miles flown. Did this happen to you before? What could be other possible reasons for this strange requirement? One of the check-in agents at BWI claimed that she does this all the time. 😂 😂. Really? She also claimed other things that I did not agree with (eg, arriving at airport three hours before flight departs). Also, she had zero flexibility on this issue. Fortunately, I swapped out the payment and made the flight on time. I also had the credit back to my bank (though it took almost a week), which was ~$40 higher than the original price. That is, I still paid for the original price for my trip.
Cheers!