My parents asked me to check in for them at T-24 to get E+ (they are Silver).
They are flying IST-FRA-IAD-ORD
IST-FRA is UA ticketed codeshare, TK operated
rest is all UA.


When I tried to checkin on the site it says it could not and I have to goto the airport. On the UA site, I tried to choose seats for FRA-IAD-ORD and it wont let me. It says I am already checked in. I then tried on the TK site, I can choose seats for IST-FRA with no issue. I called in to UA and they tell me its because I'm checked in on TK already.
I called TK to uncheckin and they said they cannot because it is UA operated. I told them it clearly is not and even gave to the TK flight number but he said he can't uncheckin. (perhaps because its UA ticketed under the UA Flight number). I tried calling UA again the second person said she doesnt see why that would matter but she still couldnt get the E+ seat. She forwarded me to the website helpdesk, they could not help either.

Has anyone encountered this situation before?
I've heard of similar issues before but you would think UA could assign a seat on 016 stock on a UA operated flight.

Interesting that every UA agent tried to tell me I was not within 24hr and I had to remind them of the timezone