Can you describe your network?

Knowing more about it can help members help you.

Since you have reset your system, do that again but this time connect your Arc to your network before you begin the setup process.

Thanks for the reply.

My network consists of an OPNSense firewall connected to a TP-Link Omada switch and access points. I have VLAN’s setup, one of which is an IOT isolated network which I’ve connected all my Sonos devices to. Moving to this network was the cause of all my issues. I thought this could be the problem so I’ve also tried adding the Sonos devices to the trunk untagged network as they were on before, but I’m still encountering the same issues.

I tried connecting the Arc directly to the router and performing a factory reset. It finds the device but then when trying to add it to the system it says it can’t be found. Is this what you were recommending doing?

Thanks for any help you can give me. I’m truly at a loss.

Sonos recommends that you have the speakers on the same VLAN as your mobile device for the best results. There is a way to make that work, but you may be  better off with the speakers on your safe network until you figure out. When hardwiring a Sonos you must have STP settings configured properly so that you do not  crash your network.

Yeah I’ve tried setting it up with my mobile device on the same VLAN as well as moving the Sonos speakers to the untagged network. The same problem still occurs. I can add all speakers, and they all play individually, but once I bind them to the Arc they show as unconnected.

It might sound obvious, but have you tried powering down and restarting the whole system: router and Sonos devices? That ensures no duplicate ip addresses which seems an issue Sonos is prone to. Then try connecting surrounds first, before adding the Sub. I seem to remember a recent thread where, for some reason, that worked. The Sub may have been powered off whilst the surrounds were added.  

Also: have you disabled wifi on the surrounds? It needs to be enabled. 

Not yet. I’ll give it a try!

An update. I’ve tried completely clearing the Sonos app data and reinstalling it. I’ve tried adding a brand new setup with everything turned off. I added the Arc then added the surrounds. The same problem persists. I add the surrounds and I can see them connected to my access point. Once I connect them to the Arc they go completely offline.

Another thing that seemed to have happened is I’ve now lost all audio from my TV through HDMI. It’s definitely connected because I can change the audio volume on the Arc from my TV remote but there is no sound. As before the Arc can however play music. I’ve tried multiple different cables with no luck, as before this was completely working previously.

I’m at my wits end with Sonos. This all worked perfectly two weeks ago and I at least had TV audio through the Arc up to two days ago before I tried to get the surrounds and sub to work. The system is in an even more unusable state than when I started this all!

Another update. I’m able to create a stereo pair with my One’s and also add the Sub and everything works fine. Once I connect anything to the Arc however the devices go offline. Is my Arc now just completely ruined? The only thing I can do with it now is play music. No HDMI input and I can’t pair anything to it.

To clarify: are you using “add surrounds”? You say you “can’t  pair anything”. Does your room have Arc and surrounds or are they in multiple rooms?

If they are a single room maybe it’s time to generate a diagnostics report and speak with Sonos support. 

Yeah I’m trying to add the surrounds and I’ve added them to the same room. I’ve also shut down all my other speakers to do a fresh install with only those 4 speakers.

Noted on speaking with Sonos support. I think it’s time. 

You stated above that you were able to stereo pair the two surrounds.  However, you cannot add a stereo pair as surrounds.  Separate the pair before choosing to add surrounds.  

After speaking with customer support I was able to get this working. Adding this here in case someone else runs into a similar issue. Diagnostics was showing DHCP proxy errors after adding the surrounds and sub to the Arc. On my TP Link Omada access points I unchecked Multicast-to-Unicast Conversion and ARP-to-Unicast Conversion which allowed these requests to go through and fixed the problem.