Too much culling happens at chunk borders when underground

To reproduce

1. Create a new world (creative, cheats on)

2. TP to -91.0 100 272

3. Standing on the surface, dig 4 blocks down. Fill in the two blocks above your head, and dig out a 3x3 little room around you.

4. Look towards positive Z, and a little to the left or right (almost towards the corner of the room)

5. If you move around a little bit and get close to the chunk border behind you, you'll see the chunks to the side disappear.

This doesn't seem to work if there's not a layer of blocks between you and the sky.

I also made a dirt box on the surface and was able to recreate the issue. Every block around you seems to be essential to reproduce, except for the blocks behind you in the chunk that disappears.