SSE Alpha/Skin bug - Strangest damned thing I've seen

[brewmasterhal]

Been playing through the game again and made my way through Blackreach the other day.

 

While I was down there, I set up some SkyUI hotkey groups so that I could equip a staff in my left hand.  No idea if this is relevant to the bug, but the glitch is new since I did that.  With a save file that's 120 hours old at this point, the bug is either related to Blackreach or the SkyUI thing.

 

The attached image tells pretty much the whole story.  Something has taken a big shit on the alpha channel handling for the game's renderer.

 

Starting from the left, you can see what my character is supposed to look like and what the glitch is doing.  Every single one of my SlaveTats overlays is causing the portions of skin with even 1/255 alpha to be completely invisible.  Furthermore, my hair textures contain alpha channels and are similarly invisible.  Notably, the full-body alpha-enabled overlay added by WetFunctionRedux does not have the same issue.  In the next two images, you can see that other cloth items with alpha simply have the alpha disabled.  This is distinct from the observed behavior with the hair, which as far as I understand is handled in exactly the same way by the engine.  This somehow means that the engine is treating alpha in three distinct ways depending on the circumstance.

 

The bugged alpha can be reversed temporarily by casting any spell that applies a shader effect to the player.  Until the next time the player's model gets updated (meaning any item equipped or unequipped), alpha is back to normal.  Using a spell like ebony skin that applies a consistent shader will seems to instantly correct the issue while the buff lasts.

 

Even stranger, while in Vampire Lord form my entire body becomes invisible.  Everything that is "skin" on the model is gone, and only the cloth and metal bits are visible.  What makes this so weird is that there should be no alpha applied to the skin of that mesh at all.

 

Anybody got any ideas about this?