The only time I've experienced this problem is when my wife calls me in her 2017 Traverse. It's the last model year of the 1st generation, so it's top end tech is miles away from our truck. Even though she's able to connect her phone to the radio, when she calls me on speaker phone I hear the echo and insist she take me off speaker phone. Plus, It's not unusual for me to say things inappropriate that she wouldn't want other passengers to hear (such as our kids or coworkers). I swear a lot and talk dirty. The only thing missing is the alcohol, lol. But this what lead me to my initial reply about your phone's microphone being on. Maybe the government was listening in on you when your call started, lol?