private static void resetWindows11Border( Window popupWindow ) {
		// get window handle
		long hwnd = FlatNativeWindowsLibrary.getHWND( popupWindow );
		if( hwnd == 0 )
			return;

		// reset corner preference
		FlatNativeWindowsLibrary.setWindowCornerPreference( hwnd, FlatNativeWindowsLibrary.DWMWCP_DONOTROUND );
	}
Checks whether the owner component returns a tooltip location in
JComponent.getToolTipLocation(MouseEvent).
flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPopupFactory.java