That is as designed as the Objects are not migrated. From the QlikSense Help:
Creating an app from a QlikView document
If you have a QlikView document, you can use its load script and data model when creating an app in Qlik Sense. Visualizations, dimensions and measures have to be created using Qlik Sense.
QlikView converter (you have this tool if you have Qlik Sense Desktop installed) - an option which was not yet mentioned. Together with script, it also imports dimensions, measures and visualisations as "Master items".
1. Open the main window in Qlik Sense Desktop, called Qlik Sense Desktop hub.
2. Click "..." on the top right
3. Choose Dev Hub
4. Choose QlikView converter
5. Drag the file, you will see the message "Document successfully processed" (click "Close")
6. You'll find you document listed on the left side, select it
7. On the bottom right click "Create app...", you will see the mesage "App created and is available in your Qlik Sense Hub".
8. Take a look at Qlik Sense Desktop hub, find the app there.
Now create a sheet and drag visualisations as a whole in or create charts and drag already created dimensions&measures.