I’ve already posted this question here Meshes are wrong placed in block that has big base point
I was recommended to create a new post in the Serengeti category and include a 3dm file with my objects.
The key point is that after block creating meshes are wrong placed. I was able reproduce this behavior on Rhino 6 WIP:
Also this is the file with the objects wrong_placed_meshes.3dm (1.3 MB)