I'm creating a map in Minecraft: Java edition, and I have a few command blocks set up to give players the Blindness effect. The problem is, it makes the screen pitch black instead of reduced vision. Not sure if it normally counters it, but it also happens when I have Night Vision on.

What I expected to happen was

I expected to have to deal with reduced vision (I have another Command Block set up to remove effects)
What actually happened was...:

It reduced my vision, but it turn made everything pitch black.

Steps to Reproduce:
1. Load 21W13A Snapshot, start world with cheats enabled
2. Use command block to give players Blindness effect
3. See the results