Everytime this mission spawns on the map, the same thing happens. All NPCs already outside are killed but a couple get stuck behind the door. Eventually, as they should, the stuck NPCs are auto-killed by the game. But the key, also, gets stuck behind the door. Only once out of 5 times running this mission was the key close enough to the inside of the door to where it could be "looted" through the door to complete the mission. Door coordinates 2013x3694 (also shown in clip)
https://youtu.be/8cD34v98cbE
P.S. - Also seems that some of the audio (repeating weapon firing) sounds maybe associated with dying while the assault turret is deployed and firing on enemies which the sound then continues after respawn with the only recourse to eliminate the sound bug being to exit and restart the game.; just an FYI/thought.