Created account specifically to report bug

Playing on Xbox

After navigating through the tunnels during "The Big Dig" I have come across a group of Ghouls, one of which is a green glowing one, the other a legendary. I am to kill a few but unable to kill the rest. When i line them up either manually or using VATS, the targets take no damage, even with a 90%+ rating on VATS. The only exception is on a Crit, but it takes next to no damage. All this with weapons that have dropped most ghouls with a single shot.

I have tried reloading, Restarting xbox from scratch, previous saves, different weapons, Power Armor, with companion and without (Dogmeat and Strong), tried completing other quests then coming back, but nothing seems to work.

PLEASE Help!