So the issue I and others here have been having with skin shaders ported from P11 being ether too glossy or not glossy enough: The glossy bsdf node has been updated as far as I can tell to have a wider usable range/curve. I remember something about this in previous versions of Blender where people complained of the roughness values being very touchy and not having much usable range. So this will affect any shader using a glossy node with any amount of roughness. Good thing is it's more usable, bad thing is you'll need to adjust all your shaders. This is something core to the cycles render engine so don't expect a retro version of the shader, just deal with it and move on. here I have an example with 9 spheres. starting with the top left at 0 roughness increasing by .1 each sphere till .8 roughness. The P12 version clearly has more usable range/curve.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740