@Bkk ********
the people who get denied are trying to get in visa exempt. <- meaning they do not have a valid visa for thailand and are trying to use one of the two free entries by land people can get in a calendar year.
Someone who had only a visa exempt entry and a 30 day extension recently went to Siem Reap for a few days, then tried to come back to thailand by the poipet border but was denied and told to fly back in.
It was the fact you held a valid visa to thailand that got you in there, because do not know of any reports of people who had a valid visa to thailand but were denied at that border ๐