Skylight passing through blocks in certain chunks

Skylight is passing through blocks in certain chunks when the chunk is reloaded. The bug remains if the chunk is reloaded but sometimes it moves to neighbouring chunks, there is a clear line at the chunk border as show in the screenshots. This only happens with skylight and no other source. The light is passing through full block, top slabs and also bottom slabs. All players on the server can see the skylight boundry. The glitched light can also prevent mobs from spawning.