Marines keep attacking me

Hello there. I have be having some particular trouble with Metropolis for H2A whenever I do the mission I don’t kil any marines by my own hand but when I get to the part after the scorpion and after you go through the valley with all the snipers and then the are that has the rockets and the ghosts and the wraiths. When I come out the other side of the tunner there is a marine walking on foot on the left and a chaingun hog. They always attack me and I can’t get past it. Only because these marines are attacking me. I have restarted the level multiple times it just keeps happening.