I tried
VISION: 20 torch
VISION: 1000 darkvision
VISION: darkvision
neither worked. Adding via map to tokens works fine.
Edit: this is Age of Ashes book4. I manually added LoS since it wasn't there. This is also an ongoing campaign, so I'm not sure what do I have to reset. I tried re-adding PCs to the CT, with no effect.