Having a VR and Non - VR display simultaneously?

As the title suggests, I'm trying to make something with both VR and non-VR components. Currently, I have been unable to get unity (currently using 2018.2.19) to have both displayed at the same time. I set the main camera (non - vr) to not target the eyes (and therefore the main display) but it only works when the headset is in sleep. When the headset is on a player, what is supposed to be the main camera display switches to the VR preview? How do I prevent this from happeneing? Thanks