After connecting to any Spotify Connect device (at home or a friend) I can still control this device after leaving the 'home' notwork and switching to LTE / mobile network. And the device is still shown up in 'Available Devices'.
This is possible until any other client in the notwork starts playing on that device again. So the latest user for a device can control it over internet as long it is online and connected to Spotify Connect.
Client 1 connects to a Spotify Connect device 'A' within a local network (i.e. WLAN)
Client 1 switches off WLAN and leaves the local network.
Client 1 can still control device 'A' over internet / mobile network.
Cleint 2 connects to device 'A' within local network
Client 1 cannot control device 'A' over internet anymore
The davice has to be taken over from another one.
Your helping sites say, that only device within the same local network can be controlled!
Please do it this way again!
Thanks for getting in touch about this. Right now, what you're describing is the way that Connect is supposed to work. We'll let the right folks know your thoughts on this - we're always looking to improve Spotify in any way, so your feedback is always appreciated.
If there's anything else we can help you with, be sure to reach out again 🙂