I opened one recently here in Phuket. They initially said no, then I let my wife do the talking. The women had to make a phone call and then the tune changed.
I just did this two months ago. Had to fill out a US tax form (the bank had the form) but that was it, aside from providing a passport and a Thai address.
Go to a different bank if they won’t play ball with you. Should not be an issue once you sit in front of someone at the bank that knows the procedure.