If you have paired your helmet with a motorbike with a TFT display (10.25'' or 6.5''), it is possible that the volume of the music in the helmet can no longer be adjusted. This is because the Bluetooth connection could not be established or re-established correctly.
To restore this function, switch your communication device off and on again.
Note: This is independent of which or how many BMW Motorrad communication systems are paired.