Upside down directional lighting in HDRP

I’ve been constantly fighting the HDRP system trying to get my lighting to show both fog and shadows when the directional light is upside down (-45 degrees), but i can’t seem to figure it out for the life of me.
Here are screenshots of the lighting with fog turned on

And with fog turned off.

Why do the shadows become disabled?
Does anyone know why this is happening, or know of any alternative to keeping my shadows and adding fog?