I could've sworn I reported this issue before, but I couldn't find it. Sorry if it's a duplicate.
I found bright areas underwater that are too deep for there to be skylight.
Reproduction steps:
Use seed 3878367825461251210. Worked on both single biome world and default.
/execute in minecraft:overworld run tp @s -40.51 53.01 98.90 -139.63 41.37
See glitched out lighting
Interesting spot over here, too (same seed): /execute in minecraft:overworld run tp @s -19.00 52.28 113.60 118.97 80.70