Any idea on how fix this glitch on no fighting in warroom [Cod4]

( sample image to show the location)

It keeps on exploding before reaching the safe door even if i ignore enemies and rush within 3 mins or clear all enemies…..when i run thru the corridor it explodes even if I have ton of time left …tried all strategy like grenade launcher and frags flashbang still can't cross

Any wisdom on how to fix it