Here is how to connect Sonos to a new router…

https://support.sonos.com/en-us/article/connect-sonos-to-a-new-router-or-wi-fi-network

If you do get a new router, then perhaps just ensure it’s not on the Sonos ‘incompatible network hardware’ list shown here…

https://support.sonos.com/en-us/article/incompatible-network-hardware

A suggestion for a router is an Asus ZenWiFi (WiFi 6) which is capable of adding other Asus hubs to turn it into a Home mesh system a little further down the line, but most routers may work fine with Sonos, that’s if they’re not on the incompatible-network-hardware list.

Maybe others will chime in here too with some other suggestions.

Thanks so much. I guess I don't understand how the other speakers work fine but this little Roam speaker won't. I assume the others are ran with cabling. I don't know I didn't install it. Thanks for the reply.

I looked at the list and didn't see the spectrum SAV1 ( I assume that's the model) listed. 

I am having the same or similar problem.  My Spectrum router model is  SAC2V2S (Sagemcom).

The problem is my Beam and mini-base are connected to my TV and my Sonos 300 speakers are grouped together as another  unit.    The wifi has two choices 5G and 2.4G and for the speakers to work correctly they have to be on the same “wave length”.  Sometimes they can be but sooner or later one set of speakers will get bumped.

My Spectrum tech rep tried to make it work but in the end said I should buy a new router that is Spectrum friendly and enough capacity to handle my needs (ie 500Mbps in my case.)  If I use my own router Spectrum knocks of $5/mth, however, if you run into problems down the road they will be limited in how they can help as theywill not have remote access to see what the issue may be.

Choose the 2.4Ghz channel for use by Sonos, which then allows the Beam to use the 5Ghz band for surrounds. Sonos doesn’t need the speed of 5Ghz for music play back, and the extra distance / material penetration of the lower frequency may help.

Back when I used Spectrum Cable, I used their modem, and attached my own WiFi router to its WAN port, it was easier as I had much more control over what was going on, over their own clunky software.