Hi @RonCranham.

Welcome, thank you for reaching out to Sonos Community.

Since the Sonos Sub is missing from the application, can you try to hardwire the Sub to your modem or router using the ethernet cable.?

Once the sub is online again, You need to set up the speaker wirelessly again Go to Settings » System » Network » Wireless Setup.

Let us know if it works. If you need help with any other information, please be sure to let us know.

Hello, thank you for your reply! I can see it on the app as a “?” So it’s already linked to my system I have two sonos ones and a beam that work fine it’s just the sub? Any idea ? 

Hi @RonCranham.

Welcome, thank you for reaching back to Sonos Community.

What I can see for the recent diagnostic report number you trigger was there is a lot of wireless interference going on in the Sonos beam.

You can check this article Reduce wireless interference to prevent other issues to appear in the future.

I notice also that you have a boost which is good, you can try to hardwire the boost to the sub if that's possible but might as well to factory data reset the sub again since you getting a “?” in the app.

Also, try to reboot the router once in a while.

Change also the wireless channel to channel 6 since few devices are using the network.

Let us know if it works. If you need help with any other information, please be sure to let us know.

Hello I ran another diagnostic because it didn’t work on either of them things sadly  1494950582 Changed the channel to 6 and 3 and 4 and it didn’t work 

I also didn’t mean to make that the answer