In my pack, Survival in Chaos, which is being reworked at Create in Chaos we are seeing in testing that chunks are not fully generating with sections sliced down the middle as shown in the screenshots.

Minecraft 1.16.5
Forge 36.1.31
UAD 1.16.5-9.2.0-forge

This is the pack in ALPHA: Create in Chaos 1.16.5-0.8.1 ALPHA

I really tried and teleported around, flown a great deal, exit and re-entered the world multiple times with your modpack and I cannot reproduce this issue at all. Nor can I figure out how this is even possible in code. Are you sure the people are not adding/removing mods or changing settings/datapacks between each testing? That's really the only way I could see something like this happening.

(I did notice trees aren't spawning under ledges when UAD is in overworld so I'll try and fix that)

Oh yeah, btw, if you just recently updated to UAD 9.2.0, that will produce chunk borders like that as I changed up the biome distribution in that version to be more balanced (made oceans not so godly rare). So if that world is a world made before 9.2.0 UAD, then that explains the issue. lmk if this is the case

(also, 9.2.1 UAD is now out that fixes the trees so they spawn below ledges. Now your world should look much, much better!)

I just looked at my changelogs and it looks like it was 9.1.4, so this issue is probably closed. BTW: The screenshots are from our test server. I will likely regenerate this week with your latest version. I'll let you know how it turns out.

As always, I love your mods.
Keep up the good work!
CM

I just made a test singleplayer world and it looks Great! Thanks!

Awesome! Glad it worked out!