So this just happened.
On 17th August, I was in Manila and got a call from my sister saying "come now". (My Mum is dying, we thought it was "it".... actually turns out she probably has a few more days in her).
So I hurriedly booked a flight to the UK - on British Airways - CX918 then BA28. About 3 hours before CX918 took off. I'm a "regular" on this route as it happens - checked in, got my boarding passes, flew to UK.... and a week later checked my account and saw the BA flight credited by bizarrely the CX one had not. So I filled in the form as you do, provided the ticket number and..... IT GOT REJECTED.
Due to "EXACT MEMBERSHIP NAME NOT ON FLIGHT PASSENGER LIST".
anyway I just looked at my airline ticket and BA didn't include my middle name on the ticket (in fact I don't even recall them asking for it). I assume thats what it is. I assume that CX will sort this out (i just sent them an email, because this is totally ridiculous).
But I'm gobsmacked they would do this to a Diamond. Gobsmacked.