@Den ****
Just to add that this also happened to me arriving on 13 November. Had paid fast track pre-screen and was taken to the desk and IO started asking lots of questions, asked to see return ticket etc and told me to stand to one side. I was then told to go to another gate and was let into the Thai passport holder line where i was stamped through without any questions. Was no extra payment but was a bit unnerving to say the least.