If delta.com allows for you to enter you FB number and it sticks, then your name, prefixes and suffixes are entered correctly. Delta's IT systems are garbage, and they fail to recognize many partner elites. I've run through this issue for years with elite accounts from Alaska and other SkyTeam partners, and quite often their system doesn't unlock my benefits.

It's not worth trying to get fixed, as whenever you call in or email, nobody will have a clue as to what you're asking for. Even if someone does manage to understand the problem, they'll almost certainly tell you that there's nothing that can be done to fix it.

Bring your card and use the Sky Priority lines, board with zone 1, etc. If someone questions you, hold your ground. If they deny you your benefits with the card, file a complaint with DL customer care.