To mention...i send 3run the shotgun model. He faced the same problem. So its no local script - sun - value - setting or something.
What we found out: Heavy scaling down model via scale_x fex helps, but no workaround cause then u would need to resize everything else
'force' model for 'receiving' light from the surface below.
and cause the shotgun is bigger, its closer than other models to the ground/ceiling. Sounds possible to me.
Maybe SuperKu can help here? Hope so, i tryed now since +- saturday 17:00