If you're having Night Vision/Conduit and Darkness effect at the same time / combining them together, it will produce a very glitchy effect and lighting.

Step to Reproduce
1. Create a new world with Vanilla Experiments enabled.
2. Do the following commands.
/effect @s night_vision 100000 0 true or
/effect @s conduit_power 100000 0 true
/effect @s darkness 15 0 true

Observed Result
The darkness effect creates the glitchy effect/lighting while having night vision/conduit effect as well.

Expected Result
The darkness effect shouldn't create the glitchy effect/lighting while having night vision/conduit effect as well.