Steps to reproduce -
Let suppose i have two access point like - Access point A and Access point B
1- Connect with Access point to A and search UPnP devices in the application.
2- Send the application in background and change the Access Point to B and open the application and search UPnP device again.
It should discover the devices list which connected to that access point, But not able to search these device which has connected with that router.
Discovery - Kill the application and open the application and search UPnP devices again.