Quote - Look at the PoserSurface node for the reflective surface. I bet the Refl_Lite_Mult option is turned on. The default value is on, but it must not be used with raytrace reflections.

If it is on, turn it off and re-render.

I would post a screenshot, but I don't have access to Poser at the moment.

I'm pretty sure I saw Bagginsbill just give you the thumbs-up, IsaoShi! Well done...

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks