https://support.sonos.com/s/article/126

General requirements

• High speed wired internet connection such as cable, fiber, or DSL
• WiFi router
• Sonos app and all Sonos products are on the same subnet

Is not there a solution??

I took one look at the issue many years ago and decided I wanted no part of it. Put my controllers and Sonos gear on the same LAN and it just works.