E82 135i - iPhone SE bluetooth audio issues when cable plugged in

[Sam_M]

Hi Folks

I have an E82 135i with Harmon Kardon and ProNav.

I can use Bluetooth audio just fine, however when I plug my Apple charge cable in to the centre console, then into my iPhone SE, bluetooth gets disabled and I'm shown this message



Image poached from this blog post of a guy having the same issue https://michaelkummer.com/tech/apple...etooth-issues/ but he's not found a solution.

I'm not trying to use audio through USB, is this just a quirk of the system or is there some setting to allow Bluetooth audio whilst the phone is plugged in?

thanks

Sam