Please enter your information exactly as it appears on your passport and then verify it for future use at a Delta kiosk or on the Fly Delta app.
I still have this problem because I haven't used a kiosk. My partner is always in a hurry to get in line for check in.
Web page delta.com says, use kiosk or Fly Delta app. I'll try the Delta app then kiosk if that fails. Any other suggestions? My flight is not for a few months. I just want to try to fix this before my next flight.