As a workaround, I set the shadow blur radius to 0, changed the light from infinite to an area light, put it at a height of 500 (for an outdoor scene), increased the scale of the light to 1000%, and increased the intensity to 400000%. The scale of the light defines the amount of blurring, 1000% at this height is moderate, 10000% is very blurred, 100% results in very sharp edges. The height will also matter.