I am working on an old house with lathe walls. While I was relocating sockets I noticed that when I had disconnected a socket all other sockets became inactive, until I reconnected the socket. This only happens downstairs; upstairs is normal. Why does this happen? Weird wiring, or an error?
Perfectly normal if you have disconnected the first socket on a radial circuit. The circuit should be fused at 16 or 20 amp if wired in 2.5.
Probably a ring upstairs. Are you doing the work live? All the sockets will/should be isolated anyway while your working on the circuit.