I had the same issue with my clutch switch. I have a GS911 and confirmed that it was working OK when removed. I found that replacing it in the correct position is critical. It is only mounted with a little grubscrew and it does not appear to locate that positively. By a bit of careful adjustment I managed to find a position where it worked again. Just a tiny bit out and although it sounds as though it is working, it doesn't when operating the clutch lever. Fiddly but all you need is a bit of patience.