I was playing through Expunge: Delphi this morning trying to get the Triumphs for not dying and not dying while solo. During the “Styx” portion, the gravity cannons just didn’t work. I had activated them and they appeared to be functional but I dropped straight down in front of the first one and fell to my death. I thought maybe I had simply missed the sweet spot so I tried again and fell directly inside the cannon peering out of the circle in front. The cannon on the other side of the area also failed to function properly. On a semi-related note in the boss area I touched the side of one of the gravity cannons and immediately was killed by The Architects even though I had full health (and thought that bug had been fixed). The other strange thing that has happened to me twice on Delphi now is the lock cubes are immune to all of my weapons. During the “Tartarus” portion I kill the enemies that are tied to the “overshields” -for lack of a better term- so the lock cubes should be able to be destroyed to bring down the barrier but they won’t take any damage from any weapon I use, instead saying “Immune” with every shot as opposed to damage numbers. I sat there shooting them both for a while hoping that the glitch was that the display of “Immune,” but nope, they couldn’t be destroyed. I had to find, let’s say, a more creative way to get past the barrier. So one glitch basically stops progress through the mission and the other cost me the Triumphs.