Hello. Im getting this error when I try take games from my bot: Unable to offer items

My shop is http://dispenser.tf/shop/18020/

And I've 3 tf2 keys in my bot (steam inventory http://steamcommunity.com/profiles/76561198061790154/inventory/ ) but I can't see them in dispenser interface so I can't take them.

I refreshed the inventory so please try again.

If you find any specific item that could not be withdrawn leave them out of trades so I could test.