Fibermesh eyebrows glitching out

ramon73

I don't understand what is going on here!

https://ibb.co/LxBjyMM

I used 2 frontal lights (Lali's scene and lights for iRay) and a basic background that doesn't reflect much light and I get this weird glitch with the Lara model from the Daz store. When I delete the hair it's gone, but I don't get why the hair is causing it as the hair is from a good merchant (I think). Even more weird is that it initially it looks okay in the iray viewport, but then suddenly the left (viewers left) eyebrow turns white like that.

 

Edit: Testing it further it is the fibermesh eyebrows itself that is the culprit of the glitch. Still don't understand why though. I have used this skin and these eyebrows before without issues. Only thing different is this new hair that I bought today. I am now using eyebrows from an other model and it looks fine now (same camera postion and lighting etc)