2020 Porsche Cayenne ELECTRICAL SYSTEM,UNKNOWN OR OTHER,SERVICE BRAKES

THE CAR CAME WITH A FACTORY INSTALLED TOW SYSTEM. I RETURNED IT TO THE DEALER THREE TIMES AND IT DOES NOT WORK PROPERLY. I WAS SHOCKED PLUGGING IN A TESTER TO THE 7 WAY CONNECTOR. THE DEALER SERVICE MANAGER ADVISED ME THAT I WAS NOT SHOCKED AND STATES THAT THE LIGHTS STATING THE 7 WAY CONNECTOR IS NORMAL. THIS IS NOT NORMAL. WHEN I CONNECT A DIGITAL BREAK CONTROLLER OR 7 PIN CABLE WITH A TRAILER THE CAR DOESN'T NOT COMMUNICATE WITH THE BREAK CONTROLLER. THE BREAK CONTROLLER EXPERT STATED THAT SINCE NO DIODE WAS SHOWING WHEN I PLUG THE CAR IN THAT THIS INDICATES THE BRAKES ARE NOT WIRED CORRECTLY. THE DEALERSHIP SAYS SINCE ANOTHER CAR WORKS THE SAME AS MINE THEY DON'T THINK IT IS A ISSUE. CORPORATE PORSCHE IS UNABLE TO ADVISE ON TECHNICAL SERVICE BULLETINS OR INFORMATION ON A WIRING HARNESS TO ENABLE A WIRED BREAK CONTROLLER. I TOOK THE CAR OVER TO UHAUL AND DID REMOTE CALLS WITH THE BRAKE CONTROLLER MANUFACTURER. ALL STATE THAT IT IS SOMETHING WITH THE MANNER IT IS WIRED WITH A 'OPEN GROUND'. THIS IS UNSAFE AS I HAVE NO WAY SAFELY BRAKE OR UTILIZE A BRAKE CONTROLLER. SINCE OTHER 2020S BEHAVE THE SAME WAY THIS IS A SYSTEMWIDE ISSUE AND THE MANUFACTURER IS NOT TAKING ACTION SO IT SHOULD BE EVALUATED BY ENGINEERING.