Gameplay normal for first 60 or so hours but now when I go into VATS the target is surrounded by a black circle and all dark as if in shadow.

Searching the Net I found a console command called "TVL" (toggle vats light) and after a target is selected (and covered in darkness) if I open the console and type TVL the Vats Lights gets turned on and the screen looks normal (well lit target in VATS).

But if I switch targets the "vats light" is turned off again.

Does anyone know how to fix this?