I also have issues with the latest update 13.1.2
Monday prior to update my car stereo worked fine for music and calls. All of my data showed on the car stereo, could see contacts in my phone book, call history ect.
After the update my phone connects to the car with bluetooth but I cannot make calls, cannot see call history and cannot see the phone book contacts either.
I have done everything apple advised and still doesn't work and they dont seem to care.
I have -
forgot all bluetooth devices and re-paired
reset the phone
reset car stereo
re-paired bluetooth again
reset network settings
reset the entire phone and reinstalled software ect
again forgot all devices, reset phone and stereo then repaired.
Still doesn't work! And now Apple want me to call the stereo manufacturer and ask them if my stereo is compatible with ios 13.1.2 !!
Yeh im sure they manufacturer is going to know seeing as there is no details I can find anywhere on what this update does to bluetooth besides supposed to fix it.
So now just wondering how long it will be before I will be able to make calls and receive calls in my car again :(