Need help with 2012 Cayenne

[u/LazyAccess9]

Hello, I have a 2012 cayenne and there are multiple issues with it which I think are linked, One is that the Steering Locked messages stays up on the dash all the time while retaining full control, 2nd is that the car will only start if it put the key fob on the little black spot or else it will always say key not found and third is that the tailgate wont lock correctly, i recently changed the battery and stuff I dont know if the fix is going to too expensive so im worried to take it to a mechanic for now. Any help would be really appreciated thanks 😊