Simple solution: rotate ground X by 0.001, slightly decrease ground height so it's below the cutoff point from the grass controller. This fixes it.

Explanation: I vaguely remember detecting, in the past, slight differences in the view matrix, I think, between self-shadow and non-self-shadow mode. It probably is somehow getting division by zero in the self-shadow mode. Maybe different hardware handles this differently, so why the creator didn't see it.