I don't have an Optix card and render exclusively CPU. I had seen the eyebrow problem with V4 and LF before and solved it but, unfortunately, I don't remember the process of how I solved it. I believe it's associated with the proximity of SSS material causing self glow and value settings. I found that if certain values are set too high for SSS, depending on the type of PhysicalSurface used for the model, the greater the chances that any skin-to-skin closeness will cause some glowing.

BTW, BB's absence from the P12 forum is due to not owning a copy of P12 and he can only render CPU. That limits his capacity to troubleshoot.