I have gotten into the brother 3 facility and it is on lockdown. I am in the bottom floor and have killed all the enemies. I can see a room with glass walls but I can’t get in. I see a vent going in but I can’t crouch down low enough to get in.
If you are in the middle of the floor jump up in the machine outside and up to the right you will find the open vent to climb in through.
You should try walking in backwards while crouched. This got me through as I also got stuck here.