Mac Mojave 10.14.2, SU Pro 18.1.1180. I have noticed this behavior with previous versions of the OS and SU, so I don’t think it is unique to my current configuration. My current setup is a recent clean install of both the OS and SU (don’t ask, please).
Scenario: Make a complex component, say a corner window molding for my house model. This has curved geometry and straight geometry. When I am satisfied, I push/pull to the proper length so that when I put four of them together, I have molding that frames my window. I open one of the components and hide the ends so I don’t see the seams. I explode all of the components, select all and make a component called molding. Here is the problem: The loose geometry in the model is still present as loose geometry and there is a component called molding in the components window. Of course I can select all, delete the loose geometry and drag the component from the components window into place. However, sometimes it is not convenient to place a complex component into a complex model and if I forget to check, I could run into problems later in my modeling process, such as purging components and losing the window molding component definition.
This is an intermittent problem so I can’t show an example; it seems to happen mostly with complex components. The one in the example has 297 entities in it, which makes it complex, but not overly complex.
Has anyone else seen this?