Hi I have a single light switch in my hall which works the single light above it and I have a double switch at the bottom of the stairs which worked the stair lights but the second switch works the upstairs hall light. Now I dropped a new 3 and e from the pendant to the light switch and wired this as brown- live, grey- neutral, black switched live and marked them up. Now the old 2 and e has the red into com on this switch. Wiring is old blue and new switch wire black red tape - L2, new live-brown & old yellow L1, lights work as they should, first photo hall switch, other two of the bottom stair switch, just want to understand how they work