Just did the mission....and we encountered some Romulans with 'God Mode'.....we were unable to do any damage to them once they reached 50% health.Is this a bug or by design?
I did the mission in a group of two last night and encountered the same issue. Second to last group of romulans before the plaza, we had a sublieutenant medic at about 25% and another solder at about 50% that would not take any further damage. After both of us pounded the medic for a while with not effect we switched to two other romulans from the same group that were still up on the catwalks. After killing those we were able to retarget the two indestructibles and they started taking damage again.