Sorry, your post doesn’t make a lot of sense to me. 

A couple of points:

The Arc uses a hidden 5Ghz channel to send data to the connected surrounds. This means the WiFi should always be turned on for both the Arc, and whichever surrounds are in use. When playing music, there are two settings in the controller’s settings for the room, either ‘ambient’ or ‘full’, which only applies to streamed music, and not the TV input. 

The Arc receives its data from the source device, via ARC or eARC, or more occasionally, via AirPlay 2. For television sources, that is. Streaming music is a different thing. Which are you experiencing difficulty with? 

Surrounds need to be ‘bonded’ as part of the Arc’s room. Follow the instructions in the controller, but it may be easier to split the surrounds into two rooms first. If you’ve set up your surrounds as a stereo set in a separate room, and ‘group’ them, then they aren’t really surrounds, and would be subject to a 75 ms delay when ‘grouped’.

Can you be more specific about your setup?

Hi Bruce,

Let me help you with my setup. Sonos arc is hardwired into my router. It is paired with a sub. The two era 100s are paired and added in the app. There was no controller included. The arc is run via hdmi to my television.  In the arc support port.

One day I turned on my TV and noticed the sound wasn't working. I deleted all speakers delete and tedownloaded the app. Paired them all together and still no sound from the TV. I read in a reddit forum that when you disable the wifi on the arc it will work again.  So i tried that. I went into the app and disabled the wifi. And the sound came back on. A few months later for some strange reason the sound wouldn't come on. I checked and somehow the arc had enabled the wifi. This perplexed me. I disabled it again and the sound came on. The past few months I have been noticing the echo again. So I checked the community forum and read that wifi is needed to avoid this.... I am in a pickle. Do I disable the wifi and endure the echo or enable the wifi and let the speakers become ornamental?

The controller discussed is the app, on your device. 

As previously stated, the WiFi/radio needs to be turned on for both your Arc and the surrounds. Whatever you read elsewhere would be in error. If you may have heard a delay, that suggests the surrounds were either not set up as surrounds, but grouped, or wired and any potential del
 

If I were to guess, there’s an issue with your TV sending the appropriate signal, consistently to your Sonos. Might be worth checking the TV’s settings, and downloading any updates to the TV’s firmware/software. Finally, I’d reboot the TV by unplugging it from the wall (not using the remote!) for two minutes. 

But I’d also recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. Don’t post the resulting diagnostic number here, they get sensitive about GDPR.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

I will take your advice and flag the support team with in ten minutes of the next error.

​@Technosquirrel 

Make sure you are selecting Add Surround (in the Arc settings), and aren’t just grouping the Arc and the surrounds on the grouping screen.

Also make sure your surrounds aren’t set up as a stereo pair.