Merchants: wrong items from vendor

[Morndenkainen]

I know this is going to sound like a joke, but I went to buy a sapphire off the vendor in the N freeport bank, and wound up with a fire emerald. You can see in the screenshot that I had the sapphire highlighted, its in the transaction box, you can see the vendor telling me what im buying and confirming the price, but when I hit the buy button to buy one, You can clearly see, that I paid the price for a fire emerald and that there's 2 lines of fire emeralds on the vendor's trade box.. Kinda hit me like a total WTF moment. Anyways, here's the screenshot cause I know nearly everyone would say im full of crap without it...