I have a 4-way switch which is connected to two 3-way switches, the
4-way switch being in the middle. There are 4 labels on the back of the switch: L1 and L3 (top left and right), L2 and L4 (bottom left and right).At one position, only L3 and L4 are energized. When I flip the switch, L1 and L3 are energized. L2 is never energized. Is this normal?