Unpassable cube run?

We just had a tier 2 cube run where the remaining 4 mobs were immune to damage. They were those large mobs that come with the green aoe pulsing puddles. Immune to all damage from all 4 of us, we tried bringing them over the puddles and that did nothing, it was an impassable floor. Ive never had this happen after many many cube runs since early release. I cant find anything on google about this so if it was a bug it seems pretty rare.

What was the floor challenged called? “Survive”?

No it wasnt survive, the timer was at zero for a long time while we just kited the mobs around trying to figure it out. It was the floor that has the green pulsing puddles that do big damage, we were in tier 3 gear and it was nuking our health. The boss just kept saying “no effect” no matter what we did.

i once had a stage where all team died after 10 seconds while fighting a boss. it wasnt a wipe skill just everyone died at once all of a sudden