You are most likely using your monitor too much. You only need your monitor for foxy and maybe Freddy but primarily just for foxy. bonny and chica have a sound queue to tell you when they walk up to the doors (they produce loud footsteps). as for Freddy she works similarly to fnaf 1. when you hear her laugh 5 times then that means she is on cam 6 and you need to shut the right door until you hear her laugh again (indicating she left cam 6).