Issues with misison six major bug

Hello yesterday while playing mission six in halo 4 on my xbox one i encountered a progression blocking bug!

Tha tbeing that when you take down the new model covi-ship ship it does not explode when it flys off, then whent he mamoth proceeds ahead the map just stops, the mammoth moves through open space but you fall to death if you jump off of it, and by the time it stops moving you vanish and are locked in place, restarting the map doesn’t fix this and i have no clue how to.

Hello? this is a major game blocking bug, i need too know if its going too be fixed!