I have had issues with my Sonos devices losing connection to my T-Mobile Home Internet service. It went on for months while I searched for an answer. The problem now seems resolfved.
T-Mobile gave me an Arcadyan KV21 gateway. Speeds were never an issue. I accumulated 1 ARC, 2 Beams, 2 Amps and a sub woofer. I could play music from a service maybe 10 minutes before the connection issues came up. Sonos answer was that their products are not compatible with LTE routers or services so I shouldnt expect it to work.
I went back to T-Mobile and had them replace my Arcadyan gateway with a Sagemcom. I hooked it up and my Sonos equipment connected and stayed connected. Problem solved or so I thought.
Then came the Prime Video streaming service issues, it just would not work. Then, another device in my home refused to connect. But Sonos still worked.
I had read that an eero mesh wifi system hooked to the T-Mobile gateway might help and finally all my devices seem to work. Cost me another $250 for the eero devices but I seem whole now.
Hope this helps someone avoid the issues I had. T-Mobiles service is fast so its worth looking into. And ony $50 month.