Hi Didler,
I dont know if you covered this, so let me know if you've already been over this.

The first model in the post you made was not a solid so the surface normals were off and it wouldnt be recognized as a volume. I did see and anomoly on the right side curved surface that I could not see or determine what it was from MoI. (It could have been something from my package that i looked at it with)



MoI has a neat script that will show naked edges and let you know where a surface is not a solid.

So I made it a solid and reviewded it and it looked much better



The second retest model looke nice from the git go.