I had a flight a few weeks ago where they couldn't find a way to add me to the list either. I don't think it would have cleared anyway but that's not the point. The web support desk said to check with a checkin agent, the checkin agent said to check with the GA, the first GA tapped away for a moment and said I was on it. Checked on PDA site, not listed, went back to a different GA who spent 5 minutes trying and gave up. Never got a good reason for why it wasn't possible.