Frontline Roulette broken?

Time: Varies
Frequency: Often
World name: Faerie
Character name: Baron Lector (me) and Baroness Lector (my wife)
Retainer name: n/a
NPC name: n/a
Monster name: n/a
Class/Level: 50+
Party or solo: Solo
In-game time: n/a
Area and coordinates: n/a
Housing: n/a
Steps:
1. Log in.
2. Sign up for Frontline Roulette.
3. Read "You cannot accept a new duty. Please try again."

This happens on both mine and my wife's character. Up until 2 weeks ago, I was able to queue for Frontline Roulettes. Since then, however, I get the "You cannot accept a new duty" message. I can queue for EVERY other Duty available to me, except for this one. I am not queue'd, nor in a party, when I try to sign up for this. I've tried logging out and restarting my PS4 when this happens.

My wife is experiencing the same thing, to a point. She unlocked the ability to queue for Frontline battles last night. When she tried to queue for one, she got the same "no new duty" message as I.