I'm not sure what happened. I do not recall changing anything before this occurred, but now SSS only works when my characters is facing the light. If her back is to it, it's as if she's entirely shadowed. Like the whole front could be appropriately shadowed but the back looked completely black despite facing a light source. Any ideas on where to start?

Sounds odd that only SSS would be affected. Can you post a screenshot?

_________________
Embers HD
Smoking Torches and Candles
Particle and Subsurface Scattering Patches for ENB (updated 17/1/2020)
flickr

Facing the light


Facing away


Uninstalling and reinstalling helped, it's less severe, but it's still present.

They Really freak out indoors.

You should really test with the default body meshes and textures (maybe one at a time?), looks like there's something wrong with either.

_________________
Embers HD
Smoking Torches and Candles
Particle and Subsurface Scattering Patches for ENB (updated 17/1/2020)
flickr

Received pretty much the same result with defaults.

After removing Enb altogether and recieving the same result, I am uninstalling and reinstalling skyrim. It just seems like the easier/quicker option

Fixed after complete uninstall and reinstall.
Edit: SSS is not currently enabled as it is still base ENB.