singularity reactor quest

I did the aetherochemical research facility dungeon then I was taken to a room with a large circle. The room had an exit point and the usual blue type flame in the middle for right clicking to choose to go into a dungeon. After completing the aetherochemical research dungeon the duty log said go into the singularity reactor dungeon. Ok, fine, I right clicked on that blue flame thing and selected singularity reactor but it put me back into the aetherochemical research facility, I ran it again. After completing it I selected in my duty finder log the singularity reactor dungeon but ended up in the aetherochemical research facility dungeon again. So frustrating. This happened to another character of mine sometime ago but I cant remember how I resolved it. After the first time I ran aetherochemical research facility I took a break for several minutes before trying the singularity reactor but I don't see how the break would affect it. How the heck do I get into the singularity reactor dungeon?

my third try worked

Good to know you got it to work. It needs to be pointed out though that the Singularity Reactor is a trial battle, not a dungeon. Although in your case I think there must have been some glitch that didn't trigger the cutscene that is meant to play before it flags the trial battle as unlocked when you did the Aetherochemical Research Facility the first time. At least you got past it so that's the main thing. :)

I think what's happening is that you simply ticked "Singularity Reactor" in the duty finder but the ARF dungeon was also still ticked, so you were queuing for both and the dungeon came up first.

It's an oddity of how the duty finder works - it's helpful if you're running the same dungeon repeatedly for loot, but not if you're moving on to the next thing afterwards.

Sounds like you had both options chosen in the Duty Finder window.