Sonos on 4g network

Additional info, SIM card in router is on Vodafone, setup sonos to my blackberry priv hotspot on O2 and all works??

Setting the Sonos up as a new 'Standard Setup' system would have wiped all your settings and playlists.

You could have followed the usual routine when changing to a new router/WiFi: plug one of the Sonos into the router temporarily and update the WiFi credentials via Advanced Settings/Wireless Setup. That would have retained the rest of the settings, accounts, playlists, etc.

Having switched the Sonos to the TP-Link router, it ought to work though, assuming there's no restrictions on the Vodafone data service. Obviously everything attached to that router would need to be powered off and on again, in order to refresh devices' network address info.

I'm in a similar position. Rural location, no fibre and 4 miles from the exchange. Maximum download speed is about 1.8Mbps but more usually 0.8 - 1.4 Mbps and despite all the promises, there is no sign of a solution for the forgotten rural community.

I set up an ASUS-4GAC55u 4G router about a week ago. I chose this because it claims to provide a wide WiFi coverage area, has two 4G aerials that can accept external aerials if required and has a host of other useful features. I'm using a Vodafone 4G SIM (currently you can get 50Gb for £30 per month on a 30 day contract so easy to cancel if it doesn't work out). Download speeds are 5x to 15x faster and adequate for everything I do, including catch-up TV. Positioned close to a window, the router shows 7 or 8 bars (out of 10) for signal strength so no need for an external aerial.

I use a SONOS Bridge (so I guess this is a BOOST set up?). I switched off all my SONOS devices and the ASUS router. Plugged the bridge into the ASUS router and powered everything up. Everything works just as it did before, radio stations, my Spotify account, play lists etc. I have a PLAY1, a PLAY3 and a PLAYBAR and can easily stream different content to each device. I was concerned that CGNAT might mess things up but everything seems to work OK. One thing to look out for is that SONOS only connects to 2.4GHz WiFi so if your router is broadcasting 2.4GHz and 5GHz, make sure any devices you want to use as controllers are connected to the 2.4GHz WiFi network otherwise they won't "see" your SONOS devices.

I would prefer to use the EE 4G network but the signal strength in my area is not as good as Vodafone and EE is currently more expensive (32Gb for £29 on a 12 month contract). However, EE do offer faster speeds and they are in the process of migrating to IPv6 so that should get around CGNAT issues and this might be a better choice for the long term.

I was concerned that CGNAT might mess things up but everything seems to work OK.
CGNAT is irrelevant for Sonos. It can be behind multiple stacked NATs.

One thing to look out for is that SONOS only connects to 2.4GHz WiFi so if your router is broadcasting 2.4GHz and 5GHz, make sure any devices you want to use as controllers are connected to the 2.4GHz WiFi network otherwise they won't "see" your SONOS devices.

You're in SonosNet/BOOST mode. Sonos isn't connecting to your WiFi at all. It's communicating over SonosNet and then via the wired connection. You can use controllers attached to either of the router's WiFi bands.

Some routers can cause problems where a Sonos system is in WiFi/Standard mode. With that setup the units are indeed connecting to the 2.4GHz band, and some routers prevent controllers attached to 5GHz from discovering the players. They block the forwarding of broadcasts between wireless segments.