Not sure if this is a bug, however when you turn elective mode on and move around your skills and then turn it back on, skills do not reset to their default type. For instance, if I choose to pick another primary skills for my right mouse button and decide I want to turn elective mode off, I am locked into choosing primary skills for my right mouse button and not secondary as it was to start with.

To me, when turning elective mode back off from having it on, all skill categories should reset to the their respective defaults.