Sonos systems use DHCP to get an IP address on your network which is liable to change over time depending on the state of the issuing device, usually your internet router or modem. This change can cause issues with automation systems like Nero that are trying to interact with your Sonos speakers. To avoid this problem, we recommend you set a static DHCP lease for each of your Sonos speakers.
Refer to your modem/router manual for steps on how to configure a static DHCP lease as this will vary by make and model.
You will require the MAC address of your Sonos speakers to configure a static lease for them. Many modems will make this easy to find, however, if your modem doesn't you can use an app such as Angry IP Scanner. Apps like Fing on iOS can no longer detect MAC addresses due to OS limitation so desktop software is required.