Some meshes do not get fractured

[evginnnn]

I'm using Unity 2022.2.4f1.
The blend files in the demo are not supported so I exported them as FBX, like the dragon. Unfortunately they do not get fragmented into chunks. What could be the issue?

[ElasticSea]

Unity needs blender installed on the system to be able to import the blend files in the editor. The imported fbx mesh might be slightly different. I remember it fails to fracture open meshes. Can you share the fbx file here?