NPC always disappears and don't reappear again

Even before the patch (and after too), in the CULTIST CAMP in Divine Era, the guy that buy and sell things, his name is KENSON, if you click him, in the beginning the shop is empty. After there are items in the shop the KENSON always disappears and don’t reappear again. I am almost pretty sure he disappears anyway, after like 10 seconds even if nobody clicks him.