Bug on twisted domain breach lets you fight boss even when breach is lost

I was playing with my friend and we went to twisted domain, I died but I could join the map again, so he died, but I couldn't get to the front in time so the breach closed, we were teleported back to the beginning of the map and everything normal, I decided to check if I could go to the boss still, but there was a invisible barrier and then I tried using blink over it and to my surprised it worked, so I just kept going through the map, blinking over invisible walls, until I reached the boss, I had a fight with the basically invisible boss... so... thats the bug, although I lost the breach on time, I still reached the boss

It happened exactly the same thing to me.
ive recorded a video. fortunately I had the teleport option with "ball lightning" and "lightning Warp"
Ive managed to kill the boss without see anything of what he was doing.