In the quest The Matriarch's Lament, the Bastille of Might closest to the realm spawn point is not spawning the 2nd wave of enemies. So the player is unable to complete the Bastille and exit.
I will travel to my respite and come back and see if i can gain entry again.
After posting this i decided to try quitting to menu and then resuming to see if that would work.
It did, when i reloaded i was still in the Bastille but now the button to proceed with the challenge and spawn more enemy waves was working again.