Affects Version/s: Minecraft 19w04b
Fix Version/s: None
Environment:Windows 10 1809
Java 8 update 201
Sometimes the torches/glowstone in a build just stop emitting light at random. Usually it happens after logging in or going through a Nether Portal.
The F3 menu reports the lighting if the torches/glowstone weren't even there.
I don't really know how to give steps to reproduce this since it just happens every now and then.