Have a push button start with a remote start and got message on display to change key fob battery and did so at 45,000 miles, and now doors sometimes lock and unlock but mostly not working so have to use backup key to open and lock doors. Dealer unable to fix. Remote start worked fine but dealer had it disconnected to recheck and still can’t find problem and now when remote start reconnected it won’t work. 2 key fobs came with car and other key fob which was never use won’t work properly to lock or unlock. Push button start still works fine. Any suggestions on how to fix or who I can get to fix?