What could be causing my landscape to flicker in VR?

In my scene here I decided to use a landscape rather than a static mesh but for some reason the tile segments flicker at opposite intervals in each eye. As you can see some tiles are missing in my right eye, but are there in my left. The ones that aren’t there in my left are there in my right.

Unfortunately I don’t want to disable stereoscopic rendering for this project because I want the performance benefit it gives. Could it be anything else? (I haven’t tried disabling stereoscopic rendering yet).

Another user posted this example gif here: