Have you tried expanding the Genesis tree until you actually locate the figures head and parent the mask to the head?
The product page states they are smart propped. I’m familiar with smart propping in Poser but am not completely certain it works the same way in DS.
When you load the default Genesis figure and the mask, is the mask in the right place? If you check the tabs, is it parent to checked?
If by default, it isn’t loading at the proper place and isn’t showing as parented, the smart propped data isn’t being read.
Have you filed a ticket and/or a bug report?