Restoring maximized modal forms

[dseligo]

I have a problem with maximize/restore of modal forms.

Lets say I have a main form, and two other forms: Form2 and Form3.
I show maximized Form2 with ShowModal, and then from Form2 I show maximized Form3 also with ShowModal.
If now I restore Form3 from maximized state (either by double clicking on title, using system menu or restore button) Form2 is also restored.

Why is this happening?

I use Lazarus 2.0.10, FPC 3.2.0, Windows 10.
I attached test project for this.

P.S.: Oh, and Merry Christmas!