We've seen that happen on multiple occasions as well, and it usually only occurs, when you're not applying 3Delight materials to your hair prop/figure, before applying RedSpec TGX Hair.
Iray materials are currently not supported,but will soon be, since Paul will work the conversion methods into the OCDS plug-in, after bugfixing and more important feature implementations were done

Thanks for your patience until then and Happy Rendering
