I noticed the following and think it could be a bug:
As usual create a mesh based on geometry - mesh (A).
Next I imported a .inp mesh file (B) and for comparison another .unv mesh (C).
Mesh (D) is a copy of mesh (B) - “Transform > Copy and translate”.
Unfortunately, when I now recreate/update mesh (A), mesh (B) disappears. It doesn’t effect the other meshes so I think it might be a bug.
The background is that I created some template meshes and stored them as .inp files which I would like to add to future geometry based models.
Edit
The problem with mesh (B) only occurs when the part referring mesh (A) is a compound and the option “Merge compound parts” is set to “YES”.
To check this see attached file: If you remesh the part, the washer will disapear. But in this case, if you switch to “Merge compound parts” - “NO”, it will also disapear. This is just because i selected “YES” first, so the result depends on the first selected setting.
Test.pmx (279.0 KB)