Hi there. I need advice on my upgrade. I recently bought a 12 speed upgrade for my 11 speed. I first double checked that the hub doesn't have to change and from what I saw, I was good to go. I thought, 'heck let's try to do this myself'. So I fit the 12 speed GX eagle and everything seem to fit, but when I place my wheel on the bike and tighten it, the cassette doesn't seem to move freely backwards. Forwards it's free though. What am I doing wrong