Did you remove your phone from the bluetooth in the car?
Also on your iPhone go to Setting>Bluetooth>find the car there and tap the ! then tap forget
There are 2 links to your car in the Bluetooth settings
1) Phone key
2) other is for music
You may want to remove both from here and the car
If it were me I would
1) in the car remove phone key
2) in the car remove bluethooth connection for the phone
3) on the phone, log out of the Tesla app
4) on the phone in the setting remove both bluetooth instances of the car if they are there
5) toggle bluetooth off and back out of the setting
6) reboot the car
7) reboot the phone
8) turn bluetooth back on in the phone
9) download and reinstall the Tesla app, log back into it
10) set up phone key and phone for music and phone again.