Metropolis Achievement in Halo: The Master Chief Collection

Anybody else having issues with this on legendary? Not that I can't beat it, but literally the game is broken and there are 2 wraiths that will not die. Neither the rocket hog or rocket launcher will blow them up. AND if you hijack one and melee it or plant a grenade in it, it still doesn't kill it. It is at the part when Cortana says there are marines trapped inside that building.

LEGENDARY GUIDE https://youtu.be/sx8ALUCU_nE