‘Wouldn’t group’ can sometimes mean they’re on different ‘builds’ of the firmware. Have you double checked that they’re all up to date? Have you called Sonos Support to discuss it? If so, what did they suggest, their ability to see data the rest of us can’t is often helpful to diagnosing an issue. 

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.

​@NicB74 

First let’s get Sonos terminology understood as I think there is a misunderstanding. If not my apologies.

Each speaker you setup as a standalone is designated as a Room. Surrounds attached to a soundbar become part of that room and no longer show as a stand alone speakers. The same applies to a sub attached to a soundbar or a speaker.

Grouping combines Rooms to play as a unit. Rooms can be ungrouped and return to previous state.

The number you see in the speaker icon for a Room if showing as “1” means that room has no other Rooms grouped to it. If the number changes to a “2” or higher that means the Room is Groped to other Rooms which will also be shown by name to left. When the Rooms are ungrouped the number will decrease by one until all Rooms are removed and the icon shows only the number “1”.

From what l saw in your pics your Rooms are set. If by missing “peripherals you mean sub or surrounds that can be fixed.

If the peripherals as you call them ( sub and/or surrounds) still show as part of the Room with a soundbar unplug them for 30 seconds to see if they reappear and function properly.

If not you’ll have factory reset them and add them to your system as follows:

Go to add a product and setup speakers to be used as surrounds as separate Rooms. Do not combine them as a stereo pair. Once set go to the Room with the Soundbar and Select “add surrounds’. The app will show the speakers you added as separate rooms . Those are the speakers to add back as surrounds to your soundbar.

For a sub go to Add a product and add it. Once done go to the Room where you want the sub and select Add a sub. Look for the sub that shows unassigned. That is the sub you want to add to the Room.

Hopefully, this resolves your issues.

Happy with the room/speaker terminology. I have tried all of the above but still joy. 🥲 

If you mean you still have surrounds and subs that are missing there’s only one other possibility. If you have an ISP provider router/modem combo and are using your own router make sure the ISP provided router is placed in bridge mode. Otherwise you have two competing networks.

Beyond that I’m out of options and I suggest you contact Sonos tech support again. Good luck to resolve your issues.

I’m using supplies ISP router, not my own, Sonos said I need the router and extender in bridge mode so they have the same IP address. Vodafone said it was in that mode, but that was one of the tech chat blokes. 
what is you opinion on the playbar needing to be hard wired?

Firmware updated, I’ll check again, thanks. 

I’m confused. Maybe it’s UK terminology vs US. Why would an extender and the router need to be placed in Bridge mode? Is the extender a device that could be used as a router on its own? If so the extender would need to be in bridge mode to extend the WiFi signal without assigning IP Addresses. Does Vodaphone not offer a pre-configured WiFi mesh system that is basically plug n play?

Thanks for all the help and advice. Brand new router from Vodafone finally arrived late last week. After Sonos help line telling me that I couldn’t use the new router and sound bar without a permanent Ethernet connection directly plugged into it, I have managed to set the complete system up with minimal hitches and it has been stable, working as it should do for two days now. Moral is don’t trust that brand new equipment is working correctly out of the box!!! Thanks for all!!