It is too bad you didn’t stick around long enough to figure out it’s your network, and not Sonos that’s the issue. 

Any network device, like the Sonos, is only as good as the network it is connected to. I suspect, in your case, that it’s either simple wifi interference , or perhaps a basic IP address issue, both of which can usually be remedied locally, without further expenditures beyond time. 

I do hope you’re able to find a music system that suits you. Hopefully, you’re aware there is a great resale market for your Sonos devices, as there are a lot of people who are willing to pay good prices for second hand equipment. 

Best of luck in your future purchases.

I have the almost the same problem than rld53 !And especially I have the opinion on Sonos. I change my routeur couple months ago for a Giga routeur provide by Bell (Canada) and connexion to my Sonos speakers (play 3 and one sl) are not reliable anymore. Try to connect my Sonos one directly to routeur for testing if a Sonos boost may help but Sonos app (s2) unable to detect play 3. And hop ! « par magie » play 3 appears in my Sonos s2 app, but not on Sonos app of my wife!! Grrrrr ! So I guest sonos boost will not help ?

I use fix IP for Sonos speakers (above 75 ) as suggested.

Play 3 connect to routeur on 5G, but it use probably a wifi 6 protocole not supported by Play 3 ?

I have not that much tool to configure Bell routeur, should I add new routeur with older protocole to make a specific network to my sonos speakers?

I have Play 3 since many years and Sonos one since 3 years but If not able to connect them anymore to my network I will have to found something else.

The Play:3 is older technology and does not support 5G wifi. Make sure your 2.4 and 5 GHz wifi channels have separate SSID’s and your Sonos devices are using 2.4GHz. Also be sure the wifi is locked on channel 1, 6 or 11 rather than auto-switching. 

PierreL,

Just to make sure that we understand: If you wire the ONE SL directly to the new router can you control the PLAY:3?  Is the old router still powered? If so, make sure that none of your devices is using the old router’s WiFi and nothing except the new router is wired to the old router.

FYI - A recent update added 5GHz support to older speakers.

https://support.sonos.com/en-gb/article/sonos-system-requirements

Actually, I did not add another router. I have only one router. New giga router replace the old one (In fact, Bell replace the router). I’m testing right now a setup based on my Sonos One Sl wired to Bell router to see if this provide more reliability.
But It was a pain having Play 3 recognized by the network using S2 app tool. I succeed with my IPad, but it was painfull to make sure S2 app works fine also on my wife’s iPad (many unplug/plug play 3). Since then, sonos speakers remain connected and stable.
So if this setup is reliable, I guest buying a Sonos boost (instead of adding a second router) to allow me to bring back Sonos One in initial room, since Boost will replace Sonos one wired to router. 

hope it’s more clear.

Now that everything is working, adding a BOOST will allow you to return the ONE SL to its original wireless location.

Your wife’s inability to control the system is a separate issue. Is she able to control the system now?

Yes, s2 app on my iPad’s wife see the Play 3 connected. So next step is to replace Sonos One by a Boost.