HDRI backdrop reflect lower black hemisphere in UE5.5

[ValkTuna]

I’m on UE5.8 with the same settings, and it seems that the black lower hemisphere still persists.

EDIT: Had to swap to Hit Lighting for Reflections. But now it seems that the lower half has a clear cutoff line in which it shades differently from the top.

EDIT2: Back on Surface Cache. Had to uncheck Visible in Ray Tracing for the HDRI geometry.

Thanks to this post here: HDRI doesn't light up environment - #19 by CoolSmek