I have been using Sonos for many years, very reliable and pretty much rock solid. My system consists of 4 Sonos Connect Amps and 3 Sonos Connects. Everything is hardwired, direct Ethernet connection from the Sonos equipment to a switch and from there to the router. WiFi is disabled in every Sonos component.

Lately I have experienced that Spotify is very slow when controlled with the Sonos app, but specifically in the connect amps, not in the connects. In the connects the volume control, skip, album cover is almost instantaneous, either with Spotify or local library. But with the connect amps volume change takes 10-30 seconds, skip 5-10s and so on when playing Spotify content. With local files works fine. Very frustrating.

spotify works perfectly outside Sonos with my phone or desktop app.

So no WiFi related since everything is hardwired, any suggestions where the problem could be? The wierd thing is that it happens only with my connect amp devices.

Also the Sonos devices have a reserved ip in my router via MAC outside the dhcp pooling, so I would say there is no ip address conflict.

Thanks