Don’t factory reset, it’s not needed.

Is the wi-fi name and password the same as before?

You’ll need to connect a Sonos player to the base Google wi-fi unit, is this possible?

As your Play:3 is a surround speaker this connects to the Sounbar via a 5gHtz wi-fi, as such I’m not sure if this would work.

Absolutely do NOT connect via a surround speaker (or Sub). If necessary buy a Boost, add it to your system and then wire to your primary Google puck.

Ok thanks all.

Reason I'm thinking of factory resetting them all is that they simply won't connect to the new Google network. 

Reluctant to buy any more sonos kit to be honest, I find it temperamental and continually needing updates.

Last house I only had sonos speaker plugged into one of the Google wifi points (not the main hub), that sorted my issues and kept the WiFi and sonos in sync. Hopefully I can do same here as the main Google hub is in same room as the surround system.

Will leave it for now and retry another day as patience exhausted for time being, if no luck then factory reset/uninstall app and try it all from scratch.. desperate times call for desperate measures! 

Thanks again all

I don’t think that you need any additional Sonos kit but it may be worth you reading my post about connection issues: Tips & Tricks - Resolving random issues impacting Sonos devices.. | Sonos Community

Why not wire the main HT device? If only as an experiment.

Sonos isn't the least bit temperamental. Mine has-been rock solid for 10 years. It sounds like you have not had a robust networking setup.

If you wire a Sonos device it would be best to power cycle all Sonos devices 

You have never had Sonos connected to your mesh  network in a way that is likely to enable Sonos to work optimally. That is not a desperate situation.  It just requires setting things up properly. 

Hello John,

I've connected one of the play 1 to main hub and everything seems to have come online OK- thanks.

I'll order a longer ethernet cable so that can reach the playbar and put the 1 back into kitchen, hopefully the playbar plugged into the hub will keep Google mesh and sonos in sync.

Thanks again for assistance

As you have wired a Sonos device, the speakers won’t be using your Google Mesh - they will be using SonosNet instead, so there’s nothing to sync with your mesh - you could just add a Boost if you prefer to not run an ethernet cable to your Playbar, but I guess it depends how far away it is from your primary nest hub/router.

As @Ken_Griffiths says, the point of wiring a device is get all the traffic between Sonos devices off of your WiFi.  The Google mesh has some features which stop Sonos behaving optimally.  For example, Sonos devices will often talk to each other directly when this is better than following a route round the LAN.  But to do that they must be on the same wireless channel.  A feature of Google mesh is that different pucks can use different channels, and the user has no control over them.  This can hamper Sonos data communications. 

I am confident that the Playbar will work as well as the Play:1, although one can never be sure how local conditions will work out.  Maybe once you have more confidence that the system is robust you will get a Boost and do away with the long Ethernet cable.  But if the Ethernet cable is not an issue you could just leave it.