having the same problem on my just bought Shelly 3M - just after the first installation I managed to read 237V of tension and seemed to work fine for a bit. Then, exploring the menus, I saw that the current-clamp was wrongly set to 50A, so I corrected it to 120A. Exploring again I updated the firmware and with the new version, no data is shown anymore, same as in the screenshot of "Sergiocz". So I tried to downgrade (I tried all the old firmware versions available) but neither the "set clamp size" buttons appear anymore nor Voltage or Ampere data are shown...
Is it:
- hardware problem --> send back and get a replace in warranty
- software problem --> any ideas?
Many thanks in advance, Cheers