MDI Child form size problem

[Amr Ashraf]

Hello guys , I have problem with the size of MDI Child form as following :
I have MDI Container form and use this code to open child form

 FrmCodes FCode = new FrmCodes();
            FCode.MdiParent = this;
            FCode.Show();

This is my child form result >> Window State Maximized

This Area on the right not filled with the child form i don’t know why .. Maximized - Center of Screen .
The second problem that the form in the design mode looks like this

The size and the spacing is so different even if the window state was normal not maximized , I use anchor property for the listbox Top-Right-Bottom and for the tab group Top-Left-Bottom , The rest controls are default anchoring .

And strange problem happens sometimes controls disappears for no reason and checked anchoring

Design

Debugging

I need two things , First Debugging And Design Mode should have the same look spacing and size wise , Second the child form when maximized fill the screen with appropriate controls sized .
Sorry guys for the long post , I’m a beginner , Thanks in advance.
My Project is attached .