Standard shader not showing when vr mode is disabled

I'm trying to make a vr app for a school project using google vr. The app can allow the user to toogle vr mode on or off. The problem is, when vr mode is disabled, the 3D objects in my scene become invisible. The materials on them with standard shaders are not being rendered. The only thing showing is the materials with Legacy-transparent-diffuse, the leaf textures on the trees and objects that are far away from the camera.

VR mode enabled:

VR mode disabled:

You can see in the picture that only the fence, leaves and faraway objects are being rendered.

I have no clue why this is happening. I would really appreciate it if someone can help me. Thanks!