Not, I think, related, the Alexa part. It does, to me at least, sound like you have network issues that need to be dealt with. And the “all updates, unplug from power, unplug ARC, etc” just doesn’t provide quite enough detail to be sure about what process was followed in that.
I’d start by unplugging *all* Sonos devices from power, then reboot your router. Give the router a couple of minutes to finish the reboot process before plugging back in the Sonos devices.
That’s a fairly easy step, which *might* solve some issues, but isn’t a silver bullet by any stretch, since we’re not really sure what’s going on.
It might be helpful to share some insight on your network. Which router are you using? Is a Sonos device plugged in to the router with an ethernet cable?
Other pieces that might be helpful could be which version of the Sonos controller you’re using, S1 or S2, and which release number. It might also be beneficial to us creating a mental image of your system if you were to share what OS the controller device is working on, including the OS release number.
I’d probably also take a look at the wifi interference FAQ, as it’s possible that some of your devices are being affected by that, either from within your home, or from external sources, such as a neighbor.
I’ve been running a SonosNet network on my system over the last 10 plus years, and have had minimal reasons to look at the network. I’m convinced that we can get your system to the same point, so you don’t need to deal with “constant connection issues” in your network.
Finally, since this is just a community site, and not actually Sonos support group’s hangout, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.
There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.
When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your Sonos system and network.