I have issues with this mission as well. Going to the Smugglerer's Gate in Muspelheim updates to the next step :
"(4/7) Discovery! Kill the Red Dragon around the gate until you retrieve the weapons shipment."
RD lvl 8, 13 and 15 spawn in the area. I have killed these guys for HOURS, and nothing drops for this Weapons Shipment.
[In fact, when I was there, another player gated in and said he had the same issue: killing RD for hours, no item drop to advance the mission.]
Anyone have any insight or suggestions? If the mission is bugged, can a Dev fix the issue?
Thanks in advance.