Shelly UNI Adc reading 36Volts always


I am trying to add Shelly UNI to my gate control box, to get information if the gate remained open.

Connection12 and 16 should be a connection which operates a small indicator bulb when the gate opens or remain open. It should give 24V.

I was trying to get the UNI board measure the voltage on these connection using the white and green wires as the UNI board wiring diagram says. I have powered the board on the AC24V-s using the black and red wires.

The problem is that the reading of the Adc input is always high and I can also see 36VDC between the 12 and 16 connections, regardless if the gate is open or closed.

If I remove the green and white cables from the connections and check the 12-16 voltage with a multimeter, it give 0V when the gate closed and 36V-s reading when the gate is open.

I have burned two boards already by trying to switch the white/green wiring in 12-16, thinking that I might not connected the wires to the right potencial.

Any idea about it?

Thanks for any suggestions.