Seems to be working correctly here. Make sure you remember to upgrade your TWS tracks to system tracks so you can cycle through them. You can do that individually by TMS fwd short over each, or if there are no system tracks you can upgrade every track on the FCR to a system track with TMS right short.
Also, I've never heard of any automatic cycling feature when a missile is fired, do you have a source for that? viper-tws-stepping.trk