I can't access a main story quest (A Matter of Tradition).

ISP:
Caiway

Type of Internet Connection:
Cable

Internet Connection Speed:
75 Mbit/s

Date & Time:
31st of August - around 19:00 GMT

Frequency:
Once (Did not reproduce)

Character Name:
Inept Wizard

Race:
Race of your character when the issue occurred.
Elezen M

World:
Coeurl

Class/Level:
Level 19 Thaumaturge

Area and Coordinates:
Ul'dah - Steps of Thal - X8-Y13

Party or Solo:
Solo

NPC Name:
Sultansworn Elite

Monster Name:
None

In-Game Time:
Unknown

Steps:
During the quest "Duty, Honor, Country" I entered the Heart of the Sworn by talking to a Sultansworn Elite. I finshed the quest, at which point the next main story quest, "A Matter of Tradition" became available from Owyne. I exited the building without taking on the quest, went to the inn at the Ul'dah Adventurer's Guild and logged off.

When I logged back in I did a few sidequests and guildleves before I noticed that I could no longer access the next main story quest. It doesn't appear in my journal or my recommendations list and the Sultansworn Elite I spoke to earlier is now gone. I can't access the Heart of the Sworn and I'm completely locked out of the main questline as a result.