Suggests, well, something is wrong…not a huge surprise for you. If your iOS device is in a case, take it out of that case. Make sure the microphones on the iOS device are not obstructed by ‘crud’, as they tend to be especially on pocketed iPhones. Reboot both your Arc, and (hard reboot) the iOS device, and reboot the router, while your at it.

If it continues to fail, call Sonos Support directly to discuss it.

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 network and Sonos system.

I turned off my hearing aids which connect to Bluetooth and that fixed it.

Interference of some type, I suspect. You hadn’t mentioned hearing aids. 

No where in the instructions is Bluetooth devices mentioned. Luckily that fixed it. 
It sounds better than the tv speakers but not by much. Everywhere it says how wonderful the Arc is and it’s a game changer etc. My wife is upset that I spent any money on them. 

I’ve got two Arcs, but each one is bonded to a pair of surround speakers, and a Subwoofer. I like them both, but sound appreciation is always in the ear of the beholder. If your wife has an opinion, it will be hard to sway that, in my experience. 

How does your Arc soundbar sound on its own without other speakers or sub woofer?

Sonos site: Featuring eleven precisely engineered internal speakers, including two dedicated height channels, Arc fires sound in all directions, rendering every whisper, explosion, and beat with dramatic clarity, detail, and depth.

Hardly the case for me!

My Arc and new Arc Ultra sound pretty decent without a sub or surrounds. We often don't even bother turning the surrounds on for the Arc unless it is for an action movie. Sub is always powered on but we often change to Night Mode to calm it down.

Ultra is too new to say much but I don't have my surrounds yet and the movie I watched tonight was not bad at all. Big impression was the voice quality, no captions, not even my usual hearing aids and I didn't miss much. Huge improvement over the Arc.