The sky is black. I tried increasing the sky brightness in the shader settings with no effect.

anything special about your situation?
any additional mods besides optifine? if yes, please remove them to see if its a conflict or not.

Also during nights I'm basically blind. I already cranked up the exposure in the post processing to 4 but its still too dark.

This is how my game looks like if I leave the exposure on the default value 1.

Also I noticed that the dynamic range of the shader is absolutely bonkers.

Things that are illuminated are close to straight white and things that are not illuminated are basically pure black.

I tried everything in the shader settings but nothing worked so far.

thats just cave fog. i black out the sky so it doesn't blind you in caves.

it triggers indoors because I cannot accurately detect "a cave" unfortunately.

you can turn it off in fog settings -> cave fog.

I am also having a similar issue (on Windows). For my case, I notice it when I am indoors and then look out of an opening. Once I go out the sky renders in correctly. This next part I can't figure out how to reproduce well, but if I go back in and look back out I will see one of 3 things. Either the shaders will reload and then I'll see a black sky, I'll see a normal sky, or I'll see a darkened sky (which lightens upon exiting).

anything special about your situation? any additional mods besides optifine? if yes, please remove them to see if its a conflict or not.

I removed all mods so only OptiFine and the Bliss shader is installed, same issue.

the lighting not lit directly by sunlight/areas in shade takes its color from the sky, so if the sky is black, so is it.

But is there a way to fix it? I tried everything in the shader config. The sky just remains black during daytime.