I am most upset!

Since this is a user community, albeit with Sonos staff as moderators, you are unlikely to get the response you seem to be hoping for. 
 

Factory resets don’t often help. But because you’ve now created two systems you will have to factory reset those speakers in the second system. After that I suggest you don’t do that any more unless recommended by Sonos support. 
 

Try temporarily connecting your speakers by Ethernet cable to the router, as it has helped in the update/setup process for others. 

Are you aware of this guide:

https://support.sonos.com/en-us/article/add-surround-speakers-to-a-sonos-home-theater
 

Add the surrounds first, and then the Sub. 
 

Let us know how that goes. 

Hello Nik, 

Many thanks for responding, I am taking a day off from fighting with SONOS s**** to save my sanity. I have also been contacted by SONOS customer service as I have tried to add a Sub3 to my system which is new, and has triggered a request for feedback. Needless to say I didn’t hold back on my feedback. Who knows if they read that stuff anyway, but at least it allowed me to vent my monumental frustrations and relieve my blood pressure.

I find it ironic that a premium product sold on the basis of being WIRELSSS and easy to install now needs an ethernet connection; what a joke!

I have had a brief look at the document link you shared and sadly I am concerned there is a fundamental flaw in the process; that being. I somehow have two systems one with the Arc in it and one with the Surrounds in it, and there is no process step to delete a SYSTEM. I feel I need to delete a system in order to force the Surrounds and ultimately the Sub3 to join the One system with the Arc in it.

My concern based on experience is that unless the two systems situation is addressed Sonos products will continue to be spread across two systems that cannot combined in one room and synch into a combined Home theatre setup.

With a clearer mind I will read the document in detail tomorrow and plan a course of action. If my two systems concerns are not addressed by its guidance I may deploy a “scorched earth approach” by deleting my SONOS account and starting over in the hope that I can establish ONE system, with many rooms that I can then combine into a SINGULAR Home theatre system.

If this fails I may well sell everything on Ebay and buy NAIM instead. 

There has to be a better way SONOS!      

Moderator Note: Modified in accordance with the Community Code of Conduct.

AIUI, when you factory reset those surrounds, the second system should disappear. Then be sure that you add them to the existing system. Put each into a different room. Then Add surrounds to the room with the Arc, and your speakers should be offered. 

You’ll also need to Factory Reset the SUB and add it to the existing system. Be very careful to “add to existing system”, don’t create a new system.

As you add the Factory Reset SL’s and SUB give them each a temporary room name. In order to easily differentiate them, be boring and give them names such as “SL_L”, “SL_R”, and “SUB”. Next, add the SL’s to the ARC as surrounds. Finally, add the SUB to ARC. At this point all of these devices will be part of the ARC Room.

​@nmcintosh63 

Your original post and response are quite long (no offense intended) so I basically skim-read them 😊.

What follows should not negate the advice given by  ​@buzz ; unless our interpretations of your post are at odds (as I sometimes read things literally as stated). A literal interpretation can at times be a disadvantage related to someone else’s true thought expression. 😊

That said what I did notice as a glaring confusion (at least to me) is why you have an S1 system running (if that is what you mean by Sonos1) ? No product in your profile requires S1 exclusively. Also, the Arc is only compatible with the Sonos App (fka S2).  Therefore, why the Arc shows in your S1 system is somewhat of a conundrum 🤔

So my question to you is:

• “Do you have any exclusive S1 products as shown below’.

If the answer is no….I suggest you do the following:

1. Delete all Sonos apps from your device
2. Factory reset all Sonos especially those you may have downgraded to S1 (doing so will make them Sonos App compatible) *
3. Download the Sonos App (fka S2) to your device and open it
4. Select  “Setup a new system” **
5. Select “Add a product” and do so for each Sonos you own (be sure to give each a unique room name)
6. After all are set you can go to room with Arc and select add surrounds and/or sub)
7. Let us know the outcome.

 * Factory reset will destroy all person playlists saved to Sonos.

 ** You’ll also have to re-setup your NAS relevant to Sonos; if you have such