Guild Wars 2

Which dungeon?
Ascalon Catacombs SM, Sorrow’s Furnace

If you are joining through the pop-up dialogue or by walking up to the entry point?
Tried both, walking up to the entry point works once, but put me in my own instance.

How many people in the party tried creating the instance?
3

Any other details you can provide?
So I just reached level 30 on my mesmer and figured I’d check out AC (for the first time ever). The AC door was closed when I got there, I joined a group, the door opened, I walked into the open door, watched the cutscene, found I was spawned in my own instance of the dungeon. I leave the instance. TP to Black Citadel, TP back to AC, I can’t enter the instance, the pop up comes up but clicking enter does nothing but close the window. Party member suggests that I relog, I log out to character selection, log back to my mesmer, still can’t enter the instance, pop up comes up again but does nothing. I TP to Black Citadel, TP back to AC again, I can enter, but I am alone again.
I leave the group. Log out completely, close GW.exe, log back in, go to my mesmer, join a new group. They go inside and I can go in by walking in, I yet again have my own instance. I leave, TP to BC, log out, login into an alt, log back into my mesmer, TP back to AC, still can’t get into AC, log in and out again, I get the pop up it still does nothing. I can get it by walking in, but I am alone. I leave the group, log out again completely. Join a new group with a friend, the pop up instantly happens (and does nothing) and the AC door is already open. I leave the group and exit GW2.exe to come write this complaint.

EDIT: I just logged in after having the game closed for about 45-60mins, logged into my mesmer, my AC door was open already and already bugged.