Try unplugging the Arc from power for a couple of minutes and reboot your router and phone. Also try removing Amazon Music from the Sonos app and re-adding it.

You can also try some of the troubleshooting steps in this article:
https://support.sonos.com/s/article/305?language=en_US

I have a similar setup and it’s not something I’ve seen when playing Amazon Music - maybe try a different router WiFi channel to see if that improves things for you. I suggest using channel 1, 6 or 11 and perhaps also try powering everything off for a couple of minutes (not standby) to setup their connections/handshake again.

If running your system on SonosNet, rather than the routers WiFi signal, then maybe try that on a different channel too, just ensure it’s channel is at least 5+ channels away from your chosen router 2.4Ghz channel. Hope those few suggestions fixes it for you.

Hello again…

I’ve tried changing my SonosNet channel and that doesn’t seem to make a difference.  

I have noticed, however, that if I also play the music on my Move along with the surround system, it doesn’t cut out on us. 

Sorry I didn’t mention the Move before.  I didn’t think it had anything to do with my problem.

A little more info about my system…  My Arc is hard-wired to my network.  (Google WiFi mesh system) The rest of the surround system (Sub and One SLs) is connected with SonosNet.  The Move is connected to WiFi

As you’re using a Google WiFi mesh setup, it is best to wire a single Sonos device only (not a Surround or Sub) to the primary nest hub/router and not wire anything to the satellites. If that’s not your current network setup, then perhaps try that configuration and see if it improves things.

This thread is perhaps also worth a read:

Sonos on WiFi Mesh