[Bug]: Possible compatibility conflict with Countered's Terrain Slabs

[Enderborn6th]

What had happened?

In a mod pack I have with Alex's Caves, I found that it sort-of doesn't load in the world. If you go too close there it would cause issues, especially if you try and have it spawn only that biome. I went and looked through my mods and found the issue was with Countered's Terrain Slabs. Not exactly sure why but it seems to be the issue. I also provided a crash log I think was for when I tried to load a world with just an alex cave biome.

Here's my mod list as well: https://pastebin.com/t05kGFAy

Minecraft Version

1.20.1

Alex's Cave Version

2.0.2

Citadel Version

2.6.3

Game Log / Crash Report

https://pastebin.com/1EPMZprR

Check List

• I have removed Optifine.
• I have installed other mods (Please also provide mod list)
• This is a conflict with other mods and no issue occurred when running standalone.