I have noticed that somewhat on Infestation missions from tier 4 to 6, that the last switch to be activated just before the end of mission that triggers a hard spawn of zombies is often bugged. There is often no possible interaction to have with that specific end switch, which results in an inability to finish the mission, because the zombies spawn doesn't appear even if you break the locked door. It requires the trigger from the switch to occur. Please fix this.