Well Done

If you want to use the Bluetooth Unit, and of course its still serviceable, you could try reconnecting it using a (ignition?) switched 12v power input.

I have not looked at the circuit diagrams but I believe the boot (switched) power output is in that area, and may provide a temporary method to try out the idea. ???

I am not sure what effect using switched power will have on the working of the MOST system as it may ruin the 'Initial Check/Handshake' when 'Initiating' on Startup.

There is plenty to read by using 'Find on Page' - "Bluetooth" on the PDF FL2 Repair & Wiring Manual.

All Wiring Diagrams are towards end of Manual.

https://www.dropbox.com/s/n0e6q5jj1l1fe2z/...6-2010.pdf FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Unfortunately the unit has been hit and miss for a few years, would work then cut out mid call and not work again untill battery discooand re connected. So I have not used it for a long time. Just don't take calls in the car. And don't want to buy second hand as will be loaded with phones and new is silly money 🤑