Shelly 1 plus starts and stops

Hi,
I have my Shelly 1 plus 12v relay control my front gate (door strike). Recently it stopped working:
on command (Shelly app or assistant) it attempts to start (can hear the click) and right after a secondary click disengaging, then in the app the “on” indicator disappears. Additional notes:

  1. Did factory reset, uninstall and reinstall,
  2. Network works fine
  3. When not connected to the strike mechanism the phenomenon doesn’t happen: remains on
  4. No change I recall in wiring