Can you clarify your setup? How many of each Sonos device do you have? Are you using the Amp as surrounds with the Arc?

Yes, for surrounds. Hope this diagram clarifies!

Running Ethernet between the amp and arc isn’t going to achieve anything. If you want to hard wire your arc it needs to go back to the switch 

The Arc will connect directly to your TV’s HDMI ARC or eARC port. The Sub and Amp will connect wirelessly to the Arc. You don’t need to wire anything to the network switch or router. But if you have connection issues, you can wire the Arc to the router or switch with an ethernet cable.

Thanks all. I’ll prefer to keep to wired as much as possible, to prevent connection issues.

Revised the diagram.

It is not recommended to wire the Amp to the router or network switch since the Arc is designed to communicate with the Amp wirelessly when bonded as surrounds (just like the Sub).

I see… ok, got it! Thanks!

Actually it should work fine with either of the sketched wired topologies. BTW the Sub connects over 5GHz to the Arc, not the Amp. 

(When a Connect:Amp is used to drive passive surround speakers it has to have a wired connection to the master HT player, since the C:A lacks 5GHz.)