Odd flat layer generates around -9950

[Nikorasu]

I keep encountering a generation glitch after traveling down to the magma cave layer at around -10,000.
A perfectly flat layer of terrain, in the style of this mod's cave biomes, generates floating in the air, inside those caves.
It seems to happen across the entire map, and looks very out of place. Lots of vines and crystals just floating in mid-air just around -9950. Perfect flat layers of this mods blocks stick out everywhere like floating islands.
Happens across multiple seeds I've tested too. And disabling this mod and generating new terrain, the problem goes away.
I posted a screenshot in the forum discussion for this mod.

[fluxionary]

this is a mapgen glitch that commonly happens at mapchunk (80x80x80) boundaries, though caverealms seems to be particularly susceptible for some reason.

related upstream issue: luanti-org/luanti#9357