FCS Pilot and Copilot Indicators

My understanding is that the green pilot-in-command indicator should only light up on one side at a time, correct?But in my limited experience so far in pre-flight, any toggling of the button(s) just produces the same flying role on both sides: either both PILOT (green) or both COPILOT.Not sure it matters too much for a single-pilot flight, as long as "my" LH side is green, but just wondering what's up and whether it should bother me more ... :( Any ideas?Many thanks.David Abrahams