I know the Thread is old, but i have the same problem with the TPanel.
Changing components (moves, deletes, adds ...) works almost correctly, but sometimes i got the panel in the designer view with no dots no components (they are hidden and selectable), but the Components exists. When I compile the Project, the Panels with all Components are visible and work correctly. I tried every option from the TPanel Component, but no Property displays my TPanel contents

But working in the Designer View with hidden components is so hard ...
Is there a trick, to display all the components correct in the Designer View?
If nobody knows about the Problem, I can upload a screenshot.
greetings and thanks for help
ankro