Right after the guys giving CPR to the dead soldier and you round the corner and fight 2 vortigaunts and then a hivegun soldier and a few more vorts, a tank comes in from the right and you go through the doors next to it and veer right and it loads.

Right there it ♥♥♥♥♥ up big time. Super long load time, followed by 1 of 2 things, either completely walled off with no door (I watched the walkthrough I know where the door should be), or an alleyway to somehow clip outside and fall off the map. Sometimes it'll seem to load right, only to load immediately again once I move and then still no door. I've loaded way back and gone through this ♥♥♥♥ several times and NO ♥♥♥♥♥♥♥ DOOR.