The issue seems to be that some chunks or objects load with a negative lighting value so instead of propagating light, it propagates darkness. I haven't found precise repro steps as the issue does not always occur in the same locations. Could very well happen during loading of the chunk.
The issue can be observed on torches that generate darkness. The torch block's lighting fx is not affected but the propagated light is. Knocking it off and setting a new one fixes the issue but not permanently. The bug might pop up again when the chunk gets unspawned and reloaded.
I have also had the issue pretty steadily with my monster spawner. The enclosed area on top of the drop should be pitch black but it often loads as full daylight. Again, loaded with a negative or inverted lighting value.
The issue is pretty easy to repro just by loading a world and walking around it. Torchlit caves or tunnels make it particularly easy to spot.
edit: Playing on a 1.13.2 world that was patched to 1.14
Michel Moreau
The issue seems to be that some chunks or objects load with a negative lighting value so instead of propagating light, it propagates darkness. I haven't found precise repro steps as the issue does not always occur in the same locations. Could very well happen during loading of the chunk.
The issue can be observed on torches that generate darkness. The torch block's lighting fx is not affected but the propagated light is. Knocking it off and setting a new one fixes the issue but not permanently. The bug might pop up again when the chunk gets unspawned and reloaded.
I have also had the issue pretty steadily with my monster spawner. The enclosed area on top of the drop should be pitch black but it often loads as full daylight. Again, loaded with a negative or inverted lighting value.
The issue is pretty easy to repro just by loading a world and walking around it. Torchlit caves or tunnels make it particularly easy to spot.
edit: Playing on a 1.13.2 world that was patched to 1.14