Replacing and connecting a three-gang switch with a socket
“I checked with a screwdriver on all the terminals there is voltage except zero” - checked how? As I understand it, they turned on each key and is there voltage in this position? Can you measure the real voltage between zero and each “output” terminal with the keys on? Did you ring the switch itself? To understand the connection diagram and the purpose of the terminals, you need to at least ring them, i.e. which terminals are closed when the key is “turned on”. If you believe how you signed everything in the picture, then the connection is correct. The phase goes from the outlet and is distributed through the bus to each of the keys of the switch - everything should be “as it should”. But while I was writing this, I had a question “how was it connected before?” Was the switch at zero? For fun, can you swap the phase with zero?