old apple connector is 30 pin
30 pin adaptors to lightening can play up. cheap copies rather than genuine apple ones frequently play up and often don't work. there's quite a bit going on is some of these small cables that the Chinese copies don't understand and so they often fail to replicate the full features BM, Merc etc. intended.
sorry can't offer much more help, running latest software/firmware on everything is often the best starting point.
check other forums as the fault may well not be BM kit (although they sometimes work together and find a work around), later offering a fix when the phones hardware is at fault and the manu can't sort with their own software updates
In UK people on ebay are "selling" firmware flash, obviously you go to them to get it done. will be someone around near you, its just finding them that's far harder than it should be
for example
"FIRMWARE DOWNGRADE IS REQUIRED TO HAVE BMW CONNECTED DRIVE/BMW APPS WITHOUT ACTIVATION CODE CODE
THIS FIRMWARE ALSO OFFERS THE FULL 7 DIGIT POSTCODE IF YOU HAVE LATEST MAPS INSTALLED &
THIS FIRWARE WILL MAKE IT RECOGNIZE A COMBOX WHICH NORMALLY GIVES THE BELOW FUNCTIONS ONCE A COMBOX IS FITTED
-6NR BMW Apps i.e Facebook, Twitter, Web Radio, Pandora
-6NF Link, Music Player in mobile section Bluetooth audio streaming
-6FL USB/Audio interface Usb playback from Usb stick or Ipod
ONCE THE ABOVE UPDATE IS DONE YOU WONT NEED A FSC CODE TO ACTIVATE THE ABOVE FEATURES "