onWindowBlur stops functioning on main window after multi-window interaction

[Marrkkyyyyy]

When implementing a tray-based application with multi-window support, the main window's onWindowBlur event handler stops functioning after the following sequence:

1. Main window is active with working onWindowBlur

2. Main window is hidden using windowManager.hide()

3.Multi-window is opened

4. User closes multi-window

5. User clicks tray icon to show main window again

6. onWindowBlur no longer functions on the main window

Steps to Reproduce:

1. Start application with main window

2. Open settings/other window using multi-window, hide the main window first before showing the multi-window:
   static Future openWindow() async {
   await windowManager.hide();
   final window = await DesktopMultiWindow.createWindow()
   }

3. Close the multi-window

4. Click tray icon to show main window

5. Try to click outside the main window - onWindowBlur doesn't trigger