Here is a render of Topmodel Updo Hair and OOT Hairblending 2.0 for Genesis 3 Females from OutOfTouch artist.
I have used and modified all settings without being able to solve the problem.
If you have ever encountered this kind of issue, I hope you can help me.
1st rendering done with Iray shaders.
2nd rendering done with RedSpec specific shaders
3rd rendering done with the Iray engine