Minecraft server light bug?

The light is extremely strange at this point and gets dark even though the sun is on 6000 ticks (12:00 pm) how can I fix this bic

Reload chunks, block update, add light source, restart server

Server restart does not help! How do I reload the chunks is there a command?

It looks like you have a shader inside. I would deactivate it once and see if the problem is still there.

I've already tried nothing

Press F3 & a at the same time