Risu the shopkeeper bug in the Anduran Caravan

I've noticed that after buying 1 item from Risu, it doesn't allow me to keep buying stuff. She's the one who sells random stuff so sometimes I wanna keep trying, but after 1 purchase, it doesn't seem to matter what it is, it doesn't let me buy anything else.
It still makes the money noise, like it's taking my gold, but it's not.