Describe the bug
dungeons can generate outside of the ground

Version Info:

• Minecraft version: 1.18.1
• Forge version 39.0.20
• Mod Version 1.18.1 - 3.0b1

Screenshots

This can actually happen with any structure. Also the vanilla structures. I could try testing for each jigsaw piece if it is in the air but that would be to performance consuming.
The best option we have is not to generate structures near cliffs, but this doesn't have 100% accuracy.
I'm already working on improvements for that problem since I started on Dungeons Enhanced, but as I said it's not possible to completely prevent it.