Shelly EM stopped working less than 24 hours after install

My electrician installed my Shelly EM yesterday with two 50A clamps and the relay connected to a contractor for my hot water service. The Shelly EM was working great today, it measured power and even turned the contractor on and off when I wanted.

This afternoon I noticed it was no longer responding in the app. My electrician is coming tomorrow to remove the device.

Is this common for Shelly EM's to fail within 24 hours?

I am going to double check the live & neutral are powered on the same phase for the Shelly as for the contractor as I want to be sure the issue was Shelly and not the electrician. Is there anything else that can cause this that I can check?

No the Shelly hasn't been proven to be faulty yet.

Is a snubber required for a hot water service? I thought this was only for inductive loads which a HWS is not.

Any thoughts on the live & neutral coming from a different phase to the controlled load being the issue?

Thank you!

Could this have contributed to the issue?