Blender model lighting issue (modders help please)

[aerelm]

Frankly, I'm not sure what could be causing that one, haven't run into it myself. Here are a few guesses on what might be the cause, but could very well be somethin completely unrelated, someone else of the 3d folk might know more about it.
It could be some botched world setting, that would be the first thing I'd try to rule out. For that, the easy way of checking is going to the World tab and just delinking it (clicking the X next to the first field there), to see if it makes any noticeable change to the lighting.
It's also worth doublechecking the Render settings , if the Render Engine is set to Eevee, make sure Ambient Occlusion is off, and at the bottom of the list under Color Management, "View Transform" set to Filmic, "Look" set to None and "Sequencer" set to sRGB.

Also here is the quick material settings I used for the last post, might be something there as well.