Lightning System Bug

There's a bug when Pointed Dripstone grow from water and grow past water, the water texture looks so bright (Like water expose on sun), but it isn't any light source

 

How to reproduce:

1. Place/find water in darkness (Best on cave, where no light source nearby)
2. Place pointed dripstone from the bottom of the water
3. Place it until reaches/past water surface

Expected result:

The water still on same brightness

Observed result:

The water suddenly looks so bright