All I want is to connect my pre-configured speakers to my new modem via WiFi (without losing my existing SONOS setup). Unfortunately, whether I use the latest SONOS app or the older S1 version, my speakers are not discoverable on either my iPad or Samsung mobile device.

After repeatedly trying the WiFi troubleshooting steps, the status lights were inconsistent—flashing white, which indicates it's either still booting or trying to connect to WiFi. I couldn't get the chime or the flashing orange status light during the connection process; instead, the setup would just stop and fail to find the speaker.

The next step was to connect to my router via a LAN connection. Success, sort of. My system finally showed up in the SONOS app, and I waited an additional 5 minutes after the white status light became solid, just in case it was still updating the firmware. Unfortunately, when I placed the speaker back on the shelf and disconnected the LAN cable, the speaker was no longer discoverable, despite having communicated directly with the router earlier. The issue seemed to be that the router didn't create a SONOS-specific network during the LAN connection.

So, I attempted to reconfigure the WiFi by reconnecting the LAN cable, which allowed access to my SONOS system. However, when the WiFi setup process launched, it prompted me to remove the LAN cable. Once I did, the system became undiscoverable again. I also tried with naming a SSID on the new router to the old routers details, I decided to just remove the old wifi network expecting the app to allow for a new one to be added, but there was still no option to add a new wifi.
After three hours of frustration, I resorted to the last option: resetting the speakers as new devices. Since it was the weekend, and I needed my music, I went ahead with it.

I finally have my speakers set up on a SONOS system, and they’re now discoverable and communicating with the app. However, my previous setup is lost. I had to rename the speakers to their respective rooms, reconfigure the EQ and True Sound optimisation, reconnect all my third-party music streaming services, and I lost all my SONOS Favourites.

Set speakers as a new device:

1. Turn off power from wall for 10 seconds.
2. Hold the play/pause button when you turn back on until a green status light is on and flashing. Flashing green status light means the new device is ready to pair.
3. The device magically appears in the Sonos app with a message to connect.
4. Follow the automated instructions. Vwallah!! 
   Warning! You will be setting up a new Sonos system, but you will finally have music.

If anyone can comment a work-around for this original issue without having to loose the prior Sonos System setup, that will surely be helpful to the next guy. Also, if there is a solution to regain the old Sonos System with the favourites, stations and all the configurations intact, please comment. Cheers!