It has to do with the new update, it can bug out if you pick up any missions dealing with the NPC, be they bottle, emmisary, or otherwise. If you get a mission to pick up items from a merchant NPC it will bug out and not let you claim any items from them until it either expires or you log out.

This has happened twice now. I buy all commodities and then cant redeem anything no matter how hard I hit f. Has only happened at dagger tooth outpost. 
If I reload into another server they will be avail for pickup. Kinda ruins my emissary runs.

Cant pick up commodities from dagger tooth merchant.