Disabling VSM / Low Global Illumination causes Landscape chunks to get culled near edge of screen

Hi, I’m trying out different lighting/shadow settings for my project. When disabling Virtual Shadow Maps, chunks of my landscape get culled near the edge of the screen. Researching further, it only happens when Global Illumination is set to 1 (medium) or lower.

Any way to fix this without raising Global Illumination? Why does Global Illumination effect this?