0W - what has happened?

Hi there,
I'm new to the forum and to the shelly's world. I'm using an EM with two 50A clamps, on the "L" wire of my heat pump and main apartment switch. The EM has been working perfectly for a couple of days, readings were coherent with power consumption, and MQTT was working flawlessly. I decided to put some fuses to protect the EM, so I unwired it (only the 220V wires) and reconnected it. AC voltage reading is good but the power on chanell 2 is always 0W. I decided to switch the clamps to see if the issue was on the current sensor or on che EM channel, and I was able to read power for a while. Suddenly channel 1 stopped working, and now it shows 0W.

I measured AC voltage on the clamps: 13/15 V, which vary accordingly to the load. EM seems to be dead. Do I have to return it?

Firmware is: Current version: 20220209-094734/v1.11.8-g8c7bb8d

Thank you in advance.
best regards.

Thank you for valuable information. I'll repeat the measurement leaving the clamps disconnected from the EM. Actually the reading was far too high even for me... I was wondering if there was any amplifier in the clamp...

Despite the time of the day, I managed to take some values from the clamps and shelly em:
Clamps VAC: 7V and 6V (mains and heat-pump)
Shelly EM "open circuit": 17V and 14V (AC).

I think the EM is gone. I'll try to have it replaced from Shelly Italy.

Thanks for your help!

Best regards.