forge 1.20.1
using wwoo as world gen.
latest mods/forge version availble. 40.2.18

so seems you have no compat with terralith or wwoo..

Most likely, it is not because of incompatibility, but rather a known issue with jigsaw generation.

https://gist.github.com/GentlemanRevvnar/98a8f191f46d28f63592672022c41497#important-info---bugs-and-rules

[...] with large structures sprawling over longer distance creates abnormal terrain distorsion, when not used with "terrain_matching", because the adaptation will stick to the level of the starting structure.

I'll try to find a workaround. Sorry for this weird sight.

I got these screenshots straight out of the "vanilla" forge development environment.
The incompatibility is more likely just due to the structure not checking if it is generating inside solid blocks or air and not burying it properly.
However, yes this problem is worsened by the more extreme world generation of these mods.

I'd appreciate it if we kept this more professional.

Anyways, this was just an early guess as I've just started looking into this issue. That does not mean I won't look into other possibilities.
I am not trying to blame others - I would not have shipped this kind of world gen if I had noticed and know that it is my fault for not testing enough.
I'll update this thread as soon as I know more.

Works fine with vanilla world. Add a world gen mod that changes heights and depths. And your mod chokes and places it's underground on top of the ground .

So not compatible with terralith or wwoo.

I'm adding your mod to a modpack with tectonic so I'm looking forward to this fix! Thank you for working on it!