If TNT explodes it has a chance to remove chunk lighting.

[How to replicate]Step one: load a random seed. Step two: blow up more than nine pieces of TNT and save/exit as the TNT is lit, upon loading up the world you will see either, The expected result: There is a crater in the ground with floating blocks. Or my result which shows all chunks hit by the TNT will have no lighting.

(credit to this image by another user, but they despite looking the same they are not, this one involves TNT)