BTW: Be careful which object is the "active one" when pasting back the copied object!
If i now click on the black i select the activity
If i NOW paste the copied object
the parent ob this object will become Activity and not the panel it came from. This is the expected behaviour
Make sure that you select the right "destination" (the panel) before pasting the object
after you paste the object now
It will become a member ob the marked panel