HelloVincenzo,
If you are trying to access the view TaskList, why not set that as your viewName? Are you using any routing in your Component.js, as a routing pattern might be directing your app to a different view.
It is worth noting that with routing in your Component.js, you can have the App.view.xml to just initialize the application and the routing will handle any redirects from the routing pattern including the initial state (index.html) as pattern: "" if you already don't have that.
<mvc:View xmlns:mvc="sap.ui.core.mvc" xmlns="sap.m" displayBlock="true">
<App id="idAppControl"/>
</mvc:View>
Best Application Practices - Navigation and Routing
Regards,
Armin