When creating MEP elements object snap does not detect snap points of elements from linked Revit files.
Users reported that object snap does not detect snap points at creating MEP elements from linked RVT files.
Only MEP elements (ducts and pipes). are impacted by this behavior. At creating 2D or 3D lines no issue like this.
It is essential as regular MEP elements are consequently being replaced by Fabrication components, and with Smart snapping in Fabrication, it is possible to snap in the mentioned way.