Generator Auto start stop function not working

I am trying to switch a DC-DC Orion using the generator start stop function. I can make it work manually, so if I start and stop the generator manually it works. I am running a duel voltage system in a Motorhome using 2 shunts, I would like to cycle the 12v battery so it is not constantly being charged, so allowing it to drop to 30% and then recharge it using the 24v battery bank. I have tried manually changing the battery SOC on both shunts with no joy. I have set the 12v shunt as the principle shunt so I am hoping the start stop function will be looking at this shunt. I must have the relay connected correctly as I can operate it manually using the GX touch. Any ideas???