Join Date: Nov 2018
Location: Istanbul, Turkey
Programs: TK Elite Plus,BAEC GGL,ITA Executive, AFKL Gold,QR Gold,HH Diamond,Bonvoy Gold,ALL Gold
Posts: 14,186
So probably, there was a flight cancellation so it led United to change the flights and re-issued the ticket.
This is the problem.
It looks like United had taken over the ticket, which means that they need to cancel the ticket and give the control over to TK.
However, I might be missing something.