Vibrant Visuals - Caustics are seen in blocks without water on top

When you use Vibrant Visuals and you look a block which receives light from the sun/moon through water, you can see caustics in that block even if that block does not have water on top

Caustics should only be seen on blocks that receive sunlight/moonlight and have water on top, not on blocks that do not have water on top but do have sunlight/moonlight.