With adding the above Code to my configuration.yaml I also got the WiFi Connection Status.
But it seems, that this is just showing ‘disconnected’ even, If my Smartphone ist connected to a wifi network.
When you use the most recent version, the battery level should already be a separate sensor, no need for a template.
Do you see your phone under Configuration → Integrations → Mobile App?
This is impossible, the WiFi Connection status was there before, the template you posted can not create this sensor.
I’d try to remove the mobile app integration, delete the app, clear cache on the phone, set it up again.