Sonos Connect Not Syncing With Rest Of System But Only When Using Sonos App

@mielbeer,
You mentioned you are using all your products on a mesh WiFi system - I’m curious as to which make/model of mesh you are using?

Anyhow… are the mesh hubs operating in ‘bridged’ (Access Point) mode to your (ISP/Other provided) main router, or is there a separate router that’s bridged (or modem) and one of your mesh hubs is acting as the local router?

I’m thinking there might be some network latency causing the audio-sync issue between the Sonos products, so have you considered trying to run the Sonos system on its own SonosNet signal with one Sonos product only wired to whichever device is the subnets primary router/hub. It might be worth exploring that option and seeing if it resolves your issue. See this LINK and this LINK too.

I do also suspect a full network reboot followed by power-cycling all Sonos products might resolve your issue aswell, but I think putting all over to SonosNet (wired) mode might stop the issue reoccurring again in the future.

If you do opt for SonosNet, set it’s wireless channel in the Sonos App to one that is not in use by the mesh hubs (if practicable) and if it proves to work better, then report back here, as there are several other things that maybe worth doing with your setup too, going forward. HTH

Is there a Line-In connection from the SONY to CONNECT?

If so, make sure that the Group plays directly from CONNECT, not CONNECT’s Line-In.

@Ken_Griffiths The mesh is MeshForce - Some cheap Amazon product.  I’ll take a look into how they are operating and I’ll try give those suggestions a shot tomorrow.  The only thing that makes me curious is that it works perfectly when using Spotify to start the music.  I’ll report back after.

@buzz I believe the Line-In is fully disabled on the Connect.  It’s definitely acting as it’s own Sonos product when grouped with the others.  I’ll double check that though!

I‘ve had exactly the same issue with my Connect since the 14.18 update - 

What has Sonos said when you submitted a diagnostic, and called them?

Per my post, “we are not aware of any delay issues caused by the updates”, “there’s a lot of wireless interference”, reboot all the speakers in turn, restart the router, switch to a different wireless channel, “our engineers will take a look and see if the issue is with the software. If it is an issue with the software it should be solved with the new updates :)“

Thanks. It’s a bit harder to follow when you’re posting data in multiple threads. Due to the large number of posts, they’re not always read sequentially. 

I haven't posted data in multiple threads (apart from above in response to your specific question to me). I simply started my own thread on my issue, and commented on two other threads that I was having the same issue as them.

FYI I was having this issue and it is now resolved: