David Dersigny
Comments
It is fixed if you reload the world from before 20w17a. Now it would be nice to be able to "reset" the heightmap from a world corrupted by 20w17a (commands or external editor) but I don't know how to do that, sorry.
Here is the savefile on wetransfer.
Reproduced this today with redstone lamps activated by an inverted daylight sensor, while the chunk was unloaded. When I came back to the chunk, the redstone lamp looked active, but did not output any light. I attached a screenshot with debug screen, note the lighting: 0 block.
I confirm that optimizing the world, with "erase cache" checked, fixes the world, thanks 🙂