What were you doing when the issue happened?

Placing the lamps

What did you expect to happen?

I was expecting the lamps to glow

Forge and Minecraft version

Forge: 36.1.32
Minecraft: 1.16.5

Bluepower version and build number

bluepower-1.16.5-0.5.244-alpha

@MoreThanHidden I indeed placed the one with inverted redstone. May it be Optifine?

Probably not much I can do if it is, although I have tested on the latest Optifine Version with no issues, could be a shader problem though.

I have shaders too, but it's not only a visual thing, even when I press f3 it doesn't show the right light level (always at 0)

Lamps seem to be working correctly. please make sure you have a Redstone signal applied or use the Inverted Variants.