ios bug for Bluetooth in cars

We think ios 15.3 has a bluetooth bug that stops connection to some car models that previously had no problems. Our Vauxhall meriva 2014 will show a call but when you try to pick up the call it disconnects the bluetooth but not the call.

We originally thought it was the iPhone 12 that had the problem but upgraded to iPhone 13 and the issue has now started again after working fine for a few weeks.

Hopefully 15.4 will fix this issue as removing the iPhone from the car and adding it again doesn't work, neither does resetting the phone.