Cannot Complete "Double Dragoon" Level 45 DRG Job Quest

ISP:
Centurylink

Type of Internet Connection:
DSL

Internet Connection Speed:
10Mbit/s

Date & Time:
Wed, April 27, 2:33AM CDT

Frequency:
Once (Did not reproduce)

World:
Balmung

Character Name:
Rowyne Moonsong

Retainer Name:
None

NPC Name:
Alberic

Monster Name:
None

Class/Level:
DRG/50

Party or Solo:
Solo

Race:
Elezen F

In-Game Time:
Unknown

Area and Coordinates:
Coerthas Central Highlands (25.7,28.3) - First Dicasterial Observatorium of Aetherial and Astrological Phenomena

Housing:
None

Steps:
After finishing all the steps for the quest "Double Dragoon", I returned to Alberic. I turned in the key items (draconian flute and horde skull). The chat log said, "Double Dragoon" complete! and I received the Drachen Armet. However, the quest is still in my duty list and quest journal with a green check mark as if it's not complete, and there is still a green check mark over Alberic's head. He will only say to me, "Your presence before me indicates you've seen the visitor. Have you aught to show for your deeds?" The key items are gone from my inventory.

I cannot abandon the quest and I cannot progress.

Also to note, I had exactly four open inventory spaces when I turned in the items, expecting I would receive the four i90 Wyrm's pieces that the quest stated would be my reward.

Also, this seems to be this exact issue.

EDIT: Logging out and logging back in restored my key items and allowed me to turn in the quest and complete it. It is apparently tied to an inventory issue, as I had four open inventory spaces and only expected to receive the four Wyrm pieces. However, I also received the Drachen Armet, which means I got five quest rewards and was one inventory space short.