Starting with a “ broken” fob

Hello, sounds like you may need to get a new key fob. Or, use the other one -- you should have two. Additionally there could be some kind of non-factory alarm or anti-theft device hooked up to the vehicle which could be causing some kind of interruption to the proper operation of the vehicle. I'd recommend seeing your dealership - the vehicle is likely under factory warranty still for any vehicle defect, and is in the best position to resolve any added devices when sold also.