Sorry for reviving old thread.
I added my EWR-IST-ZAG AV PNR in checkmytrip dot com and it shows origin as JER instead EWR.
Also, I could not look up the reservation with either AV or TK PNR on TK website. So following this thread, I tried to access it via TK app and it let me see it. I had to add both passenger etkt numbers every time I made a seat selection. (I had selected seats when booking thru LM but tried it anyway).
So it seems that the etkt has been issued by LM and received by TK.
Now I am only worried about the wrong origin airport on checkmytrip. Any idea why it might be wrong airport?