Skylight does not propagate across certain chunk borders upon world generation

this happens to me a lot

See MC-199966 for proper reproduction steps for this particular case seen here.

I assume that since this is like MC-228592 on a chunk border, this would be a duplicate of MC-172980.

Can confirm in 21w41a.

This sometimes can occur randomly upon exploring new chunks, without reloading the world as described in MC-199966.

Can confirm in 21w43a.

Seems even worse in 1.18/1.18.1

I loaded my world in Optifine 1.18.1 and encountered this light issue, only a having a light source our vertical skylight fixes it, but it came back when the light source was removed. Though, if I loaded the world in vanilla Minecraft with the light source still there, even after removing the light source, the area where the light propagated becomes normal. I re-created the world in vanilla Minecraft alone and the area with the light error was resolved, so either you have loaded it in some mod like Optifine or Optifine, or the issue is inconsistent.

One thing I have noticed on this is that it can be temporarily fixed by optimizing world, but then it seems to happen again once a world is saved and reopened. This has now happened to me on multiple worlds and often happens in the same places.

Can this still be reproduced in 23w17a?

Cannot reproduce in 23w18a