Hey guys I've narrowed this down to Base Color/Diffuse or possibly Scatter, I'm not sure exactly which but it's causing the hair to glow under dark lighting...it doesn't appear to glow under low lighting, but it does appear by default to be brighter when you step into a darker area...after a lot of tweaking I got it looking better but it still looked really, really bad. On top of that I then noticed that this may be directly linked to the Blend Modes on their Material. It seems to be the root of all the hair issue's and there is an ugly glowing of the roots which make them appear to glow white.





The last photo was with Color/Diffuse disconnected

Deprador, was the cascading shadows setting on the lights you were using, or was it a setting on the material itself?

It was the cascading shadows; they don't use Lumen and Lumen currently doesn't support Trancluent or Masked Materials properly. It also has issues with Ambient Occlusion Textures and Roughness Textures at times.