Loader {
    id: loader
}

Button {
    onClicked: loader.sourceComponent = component
}

Label {
    text: "before"
    Connections {
        target: loader.item
        onAccepted: console.log("this does not get triggered")
    }
}

Component {
    id: component
    CustomObject {
        onAccepted: console.log("if I add this, this does get triggered")
    }
}