Similar thing happened to me when our travel agent booked me with the wrong DOB. DL would not let me check-in at T-24 because they saw I was a minor (the wrong DOB was in 2014). I contacted DL on twitter and they changed the DOB in the record and then I was able to do OLCI, got TSA precheck and no SSSS either. HTH.

Edit to add: having a DL skymiles number did not help in this case apparently. I am not sure what the travel agent's workflow is, but I had both the correct skymiles number and wrong DOB in the record at the same time.