World space canvases get culled in a weird way when moving camera.

I create this hex grid of hex prefabs. Each of them have a world space canvas with a child containing a ui text component. For some reason the text gets culled in this wierd way when I move the camera around.
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Orthographic camera works fine if it is at a 90 degree angle. But I need a regular perspective camera and that results in this wierd behaviour. Anyone who has any idea why it does this?

Turns out having a mesh with an unlit material behind a UIText component result in this behavior. I replaced the material with one based on the standard shader and now it works without a problem.