While digging I can notice a weird light behavior, the lowest block close to the ground is weirdly darker, especially when dig in a diagonal (staircases, for example). 

One interesting point: even adding a torch to the block still doesn't light it correctly. 

Here's a video showing it: https://youtu.be/yypwzz99E88
Also an image: https://imgur.com/gallery/STwTYVR

Extra info
Snapshot: 23w18a
OS: MacOS 13.3.1 (a) (22E772610a)
No resource packs installed, no mods installed.