Good morning All,
After suffering the same issues as most people, I’m a 2017 BMW 5series driver and i upgraded to 11.2.5 and apple car play disappeared as well as all the memory function in the car (pre-set radio, audio bass treble, nav, car settings etc - all the iConnect settings), even tried another phone that was not upgraded.
After speaking with BMW, booked my car in for checks. I was informed the 'head unit - control centre' had lots of faults in it, maybe coincidence however the car was only a few months old, i done the iphone upgrade and it all failed.
The end result was it was easier to replace the head unit - control unit, than fix all the faults, a new head unit – control unit was ordered and the software all reinstalled.
I also upgraded the phone to 11.2.6, glad to report everything is working again.
Personally i say the software needs to be reinstalled for the head unit - control unit, or faults cleared and rebooted.