Not so Smart Sargent Controler

I have a 2021 Broadway FB and have often wondered if when the Active Battery is set to Vehicle would the smart setting change back to Leisure before it's too late. So with MH on front drive I gave it a test. After the second warning which is Very Low Vehicle Battery the voltage was 11.1 and the vehicle started no problem. I then discharged battery further until the Sargent Controler switched over to Leisure, the vehicle now would not start. Interestingly just a half hour of Solar at about 3amps was enough for vehicle to now start. If I was not selling the vehicle in September I think it would be worth fitting an independent voltage cut off, hopefully then when the Sargent senses no voltage from Vehicle Battery it will change to Leisure anyway. If we hear the first Low Vehicle Battery warning I always switch over at that point but interesting to know there is a second warning that still allows enough to start the engin.