that is not a bug, your remote proximity sensor needs to be configured, set it to something like Trigger on Friendlies or Trigger on Enemies.

Sorry, I've misspelt the name.
I mean the remote controlled switch, not the sensor. Sensors seem to be fine.

As seen in the image, these kind switches don't form a connection line next to a wire. When put between two wires, they just "divide" the net into two unconnected graphs.

Nope, you've spelt it fine. the remote switch needs to receive a signal on the matching channel, your signal source being the remote proximity sensor.

any switch that is off (even a vanilla switch) wont appear to connect.

in the picture the remote proximity sensor is red, so it's not transmitting a signal, so the remote switch will be off as there is no signal.

just make sure the channels are matching if you've been changing those settings, drag a pawn over to trigger it, the remote proximity sensor should turn green, and the remote switch should light up.

Thanks a lot! I've figured it out now with your guidance :).
I've never noticed even vanilla switches had this counterintuitive quirk.