Basic Lighting Inaccurate

I create an empty level.
I create a cube at 0 0 0 that’s 20 20 1 in size (floor)
I create a point light at 400 0 200
I create a cube at 500 100 90

The shadow makes the cube appear floating though it’s not (shadow doesn’t touch corner of cube).

I tried playing around with Light Density and other settings (don’t really understand them) and that made it even worse. And even worse when you Build it. The shadow is all wiggly. I don’t understand why this would even happen. I mean, why would light hitting a cube create wiggly lines?? Makes no sense to me.

What the proper process for setting up a simple scene like this? Shouldn’t something this basic work out of the box?? This example is from a textbook and their screenshot looks right, no extra steps mentioned. Using latest engine.