Upon journeying through the nether a bit, upon return torches are not dispersing light. Attached screenshots of the problem

in 1.14 or 1.15? is the environment completely dark or the light does not update? does lava flow at that area? do pigmen move on their own? does relogging fix this issue? does this issue always happen or randomly happen?

1.15. Nether seems to be completely fine with lava flowing and pigmen behaving normally, just overworld. It seems to be consistently happening everytime I move a decent area away from portal. Going to main menu and then reloading solves the bug
Also, this is my first time installing fabric, and so I may have a bug not related to your mod. If you are unable to recreate it I can try some more troubleshooting on my end.

I haven't tested 1.15 throughly. I will check it later today.

I can reproduce this issue now.

Yeah, with 1.15 being a new release I was under the assumption that it was a new bug that hasn't been discovered yet

I probably fixed this issue. (I'm not sure because it's quite random)
And I reduced some lag spikes caused by client light info update.

And I found more rendering bugs.

And 1.15 changed chunk rebuild schedule policy, It builds more chunk on render thread and results in more lag spikes when the player crosses a lot of portals quickly. I am going to change it a little bit.

This lighting issue is more complex than I thought. I didn't fix it from the root cause. So I update it every 5 seconds. You may still see this issue in the new version but it will be fine after 5 seconds.

Ok, sounds great. I was going to say waiting 5 seconds gets me to a playable stage, but I am currently unable to recreate that bug. Thank you, it is a great mod