Last night I progressed to the Heart of Rage mission. I got to the point where I was fighting the Monitor in the acid pit. It got to the point where I was supposed to continue to the next battle venue, but the monitor froze in the acid. I continued to the next battle venue, and the monitor was invisible and I was taking damage. I'll try again this afternoon, and report if the issue continues or resolves. I really like the campaign, but haven't touched much freeplay, and I have no time in the strongholds. I really hope all this gets ironed out because I'm having a good time playing the game.