Originally Posted by
Often1
1. As to your situation, there is a very limited possibility of being deselected from Pre-Check eligibility. This can happen randomly or for a reason. Presuming that there is no reason for your deselection, it likely won't ever occur again. Don't give it a second's thought unless you are denied again..
I would say it is more likely due to poor IT implementation.
Having Pre
✓ logo on BP means absolutely nothing to the scanner. You only get Pre
✓ if the following conditions are met:- The Pre✓ eligibility flag is properly encoded into the barcode and
- The barcode contains an authentication signature correctly signed with airline's private key.
The problem is likely airline shoddy IT for including the Pre
✓ logo without actually encoding the barcode correctly.
Case in point in is my AF BP from last year for CDG JFK has Pre
✓ logo on it but the barcode itself is not signed.
CX barcode originating US contains authentication signature but originating HKG do not.
I agree with UKtravelbear that having UA reprint would have likely resulted in desired outcome because even if LH did sign the BP on the UA flight BP, TSA scanner could have failed it because it was expected a UA flight BP to be authentication signed using UA's private key.