Booked YYZ-ATL-IST-ATH for October with segments on AC / TK / A3 respectively. Initially the IST-ATH was showing space on TK as well but when I called to book neither of us could see it any more. I'm seeing the TK space back now and called in to change the segment but the agent on the phone said it was blocking her and claimed it was phantom space. I can make it all the way through to the payment page online with the seats either as their own reward or married to an ATL-ATH ticket (ATL-IST-ATH). Is it just a matter of HUCA until I get someone who knows how to fix the error that pops up, or is there something specific I need to tell them (or something I'm just missing...)