You used the Copy/Monitor tool to monitor elements, but you cannot see them in the current view.
Issue: The Copy/Monitor tool is typically used to coordinate changes made by teams of different disciplines (architectural, structural, and MEP). By default, many project views display only elements related to the relevant discipline. For example, structural plans only display structural elements; they do not display architectural elements.
Solution: To ensure that you can see all types of elements in a view, change the discipline for the view:
This setting ensures that the view displays elements for all disciplines (architectural, structural, mechanical, and electrical).
If you still cannot see the monitored elements: