QML Connections signal notifications

Main.qml

PageStackWindow {
    id: rootWindow

    property int checkVar: 0

    function fn1() {
        checkVar = 2;
    checkVar = 1;
    checkVar = 0;
    }

    CustomComp {
       id: c1
    }

    onCheckVarChanged: {
        console.log("cvar changed in root window "+checkVar); // here it prints only 3 times
                                  // which is correct
    }
}

CustomComp.qml

Item{
    Connections{
        target: rootWindow
        onCheckVarChanged:{
        console.log("cvar changed in root window printed in custom component : "+checkVar);
            // here it prints twice for each change ie., 6 times.. why?
        }
    }
}