I never noticed a dynamic hair setting in the exporter... but I was only using the "Basic" intro option to begin with. You'll note that the issue is that the brows and lashes are white on two of the figures (some sort of transparency issue, or...?).

Lights - Outside I have one infinite light set to both sun and sky. Inside I have one (unscaled) point light over to the left of the image as seen, and one spotlight (colours are each set around .75 and intensity @ 64%). The point light has 100% intensity, but there's obviously not much light coming from that direction anyway. If it's a light issue, it's definitely the spotlight....

Yes, it's an indoor scene - see the chairs, tables... the walls aren't super obvious in the render, I guess.

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Hardware: AMD Ryzen 9 3900X/MSI MAG570 Tomahawk X570/Zotac Geforce GTX 1650 Super 4GB/32GB OLOy RAM

Software: Windows 10 Professional/Poser Pro 11/Photoshop/Postworkshop 3