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Question

Sonos Arc repeatedly drops off network, taking entire surround group with it — firmware 18.4

  • June 2, 2026
  • 4 replies
  • 28 views

Hardware:

  • Sonos Arc (firmware 18.4, build 95.0-77060)
  • 2x Sonos Era 300 surrounds (firmware 18.4, build 95.0-77060)
  • Sonos Sub (firmware 17.2.5, build 86.7-77050)
  • All on dedicated Sonos VLAN, UniFi UDM Pro with U7 Pro AP, all devices AP-locked, static IP reservations set

Problem: The Arc repeatedly drops completely off the network, bringing the entire group down with it. The app shows all four devices as "Not Connected" and a full power cycle of all devices is required to recover.

Network logs confirm the sequence every time:

  1. Arc drops off WiFi first
  2. Era 300 surrounds and Sub immediately start disconnecting and reconnecting, trying to find their controller
  3. Entire group unavailable in app until power cycled

The Arc is most likely the root cause, the surrounds and Sub are just reacting to losing their controller.

Signal and network are not the issue:

  • Arc shows excellent signal (-27 dBm) when connected
  • All devices have static IP reservations
  • All devices AP-locked, no roaming
  • No firewall rules blocking traffic
  • All other Sonos devices in the house (Beam, Play:1, Play:5, One, Roam) are completely stable on the same network

Example timestamps from UniFi logs:

  • May 29 20:32 — Arc drops, surrounds and Sub start thrashing within seconds
  • May 30 20:02 — Arc drops, same pattern
  • May 31 00:58 — Arc drops, same pattern

Ask: Is this a known issue with the Arc on firmware 18.4? Has anyone else experienced the Arc's network stack crashing periodically while eARC audio continues working? Is a fix planned?

4 replies

AjTrek1
  • June 3, 2026

As you believe the Arc is at fault and not your network. I suggest you run a diagnostic and make note of the Reference ID (do not post it in the community). Call Sonos support as they have tools to analyze the data. Hopefully it is a network issue and not a failing network interface card (NIC). Best of luck!

EDIT:

To your question...We in the community cannot verify that what you are experiencing is a “known issue” of any sort.  We are not technical support.

 


Stanley_4
  • Grand Maestro
  • June 3, 2026

I don't pay much attention to versions, app or firmware, just always updating to the latest releases. That would be my suggestion to you as a first try at a solution as getting help with old versions is difficult. 

The Sub and surrounds hunting around with the loss of the Arc isn't something to worry about as they are trying to deal with the loss of their primary network connection, the 5 gHz Sonosnet generated by the Arc.

Have you observed the Arc when it drops off? Any change in the solid white status light? 

Have you confirmed the power cord is fully seated in the Arc socket, often folks don't push hard enough to get it fully seated. A light touch of DRY silicone lube on ONLY the outside of the cords molded end can help reduce the needed force. Wet or greasy lube will make a mess, don't do that!

As you have reserved addresses already that isn't the issue but it may be something else network related or a glitch in the Arc, a diagnostic sent and a call to Sonos may reveal something.

I avoid complicated networking so I am little help there.

There are a couple good posts here about Ubiquity best practices that you could check  to see if your settings match.


Airgetlam
  • June 3, 2026

Could also be potential wifi interference , particularly from outside the network. Hard to tell, without access to the hard data we’re not exposed to, when you submit that diagnostic. 


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  • Prodigy II
  • June 3, 2026

Hardwire the Arc by Ethernet, and remove the static IP addresses on the surround and sub. They aren’t needed as they get their signal directly from the Arc, not your router.
 

If you can’t hardwire the Arc, then try just removing the static IP addresses from the surrounds and sub anyway. That could be causing your Arc issues.