Originally Posted by
yonajon
So is the issue I am facing because I bought a low fare class (T)? Again, I'm fine to pay for the preferred seats, but it won't even let me select them.
No, T class fate is semi flexible. It is most likely because the seats are withheld by TG for allocation by Load Control, or they have already been sold. Possibly available at T-24 online if not sold.
You could always just contact ThAI (by phone) and ask.