Transparent gap in fairing mesh

[Rodg88]

This gap in the mesh seems to be something that happens when the fairing shell starts on the top of the base, instead of on the outside, maybe to do with the geometry of the particular curves on those fairings:

In-flight it's not transparent, but has an odd black colour on that part of the mesh:

And in the VAB, changing the part variant/colour scheme updates it and the transparent part becomes viable with the dark colour:

KSP_x64_1qSvtGTIzt.mp4

Some profiles have larger transparent sections than others:
https://user-images.githubusercontent.com/2611674/199508663-5a68041c-dd17-4baa-88c9-5db7b42d0fd8.mp4