In 1.1.89, LuaEntity::copper_connection_definitions (support for distinguishing between left and right side of a power switch) was added but I don't know if it relates here:
Using disconnect_neighbour on an electric pole which is connected to the right side of a power switch does not work (WireConnectionDefinition.target_wire_id = 1).
However using disconnect_neighbour on the power switch (WireConnectionDefinition.source_wire_id = 1 and WireConnectionDefinition.target_wire_id = 0) works.
[1.1.89+] disconnect_neighbour on power switches
Re: [1.1.89+] disconnect_neighbour on power switches
Thanks for the report, issue is now fixed for 1.1.95. From what i was able to observe when requesting electric pole to disconnect from right side of a power switch, left side was being disconnected instead.