Adding MP # to a TG Booking
 

I'm booking a flight BKK-HAN and it will not, simply will not, take my UA MP number; I finally got fed up created a TG ROP number just to put in there and thought I'd call and let them fix it. BUT, before I go around in circles with TG is there anything I should know why this isn't working? I can easily select UA for the FF #, but it states my FF # is not valid. It's very valid.

I've never had an issue putting my UA number in TG bookings. Worked fine and my *G showed up on my TG boarding passes.
Are you booking directly with TG?

(I also never got credit for my last 2 domestic TG flights on my UA account. Sent a message to 1k desk who were supposedly following up with it, but never posted).

Yes, direct with TG, and has happend on two separate PNRs now. Edit: TG contact center added it easily and it shows online. When asked about the problem she had no clue, and being in 'revenue only' was going to start transferring me around. As I could see it on the res online already I didnt push my luck, thanked her, and thats that.

Actually, just checked and the 2 flights did eventually post.