Anyone else having a lighting bug where in caves and under blocks where the sun don't shine, it shines anyway (Meaning that the daylight basically shines down though blocks and into caves, causing them to NOT be dark)?
Yes, I'm having that same issue.
This is a know bug when updating 18w16a worlds, see MC-129725 for more information.
I'm having a similar issue, but it has spread through my whole client. It's like I have Night Vision at all times, except the sky is unaffected.