I have dealt with this issue in the past, but the solution I used to suggest no longer works. I had to reformat between 4.16 and 4.17 so I don’t know if it was something altered or if I am simply missing something.
The half-capsule has smoothing, the cubes do not.
Some cubes use per-facet mapping, others use various of the auto UV options in Maya.
The result is the same at every shadow quality level, and in high, ultra, and cinematic engine settings (I haven’t bothered with lower)
How are others removing the shadow-warp?