QMainwindow accepts drop events even when a modal dialog is open

Even when the QMainWindow is blocked by a modal dialog, the window is accepting the drop events performed.

I have made a small application to demonstrate the same. In the application, the main window is set to accept all drop events and as soon as we drop something, it prints "Item Dropped" in the application output. When the push-button at the center is clicked the main window will be blocked by a modal dialog. But even then if the user drags and drops something in the main window the window is accepting the drop events and the text is getting printed.

Isn't it against the principle of modal dialog: "A modal widget prevents widgets in other windows from getting input."