After the S7 patch, the whole Coliseum episode become really problematic to play.
The AI never act, refusing to react, even if is a npc or a enemy. The whole episode come with a heavy lag. You walk for 1 to 3 seconds and are throw to the begin of the episode, forcing you to walk all way back.
The enemies never die, because you have too much lag to hit someone, and after 5 seconds, every enemy hit drain all of your shields and life.
Because of the lag, you can "fall" inside of walls and rocks, being stuck and can't finish the episode, forcing you to leave and back to fight against the lag again.