SubDFromMesh iteration

I’m trying the SubDFromMesh command.
I have a closed mesh with only quads and without naked edges.
If I use the SubDFromMesh command 2 times (Creases=No Output=Mesh DisplayDensity=1 AddController=No), I don’t obtain a closed mesh.
Moreover, different result is obtained applying SubDFromMesh to the starting mesh using DisplayDensity=2. Is this correct? Finally the mesh DisplayDensity=2 is Open (double precision polygon mesh), but I can’t find holes.
SubDMeshTest.3dm (11.0 MB)