Compute shader (deformer) going crazy with SubMesh only when applied on multiple meshes??

This one is quite weird, so I have this compute shader that is deforming a Mesh and I'm then using a MaterialPropertyBlock to send my position buffer to a shader.
Everything was working fine until I had submeshes in the party.
The funny part is it's still working fine if there just one Mesh with submeshes in the scene,
but as soon as I add more the deformation in screwed up for thoses (but the ones without submeshes are always OK).

multiple meshes (no submeshes) ->OK
one mesh with submeshes ->OK
multiple mesh with submeshes ->Broken

Is it a limitation, or could that be a bug?
If someone have a workaround I'd be more than welcome!

Thanks