audio issues

[tekhnologia]

Main issue
Over the past 2 months i've owned this car, there has been 3 instances in which audio will not work.
No warning messages, no chime when I open the door, no audio from car play and as a sanity check, no audio from FM.
Resetting idrive wont work, nor has any of the typical stuff when I search this forum.

So far for each instance, the only thing that would work would be locking the car for about 30 minutes and coming back and boom, it's working.
Any idea what could be initially starting this? I had a software guy remote in and digitally check the amplifier and a few things, and everything was showing green on his end.

Minor/Potentially related issue

When the car auto switches from battery to petrol while driving, there will be a 1 second loss of audio... i've driven plenty of hybrids in the past, and this is the first car to do this to me.

Is there a work around or a fix for any of my two problems?

[Clifton]

How old are the 12V batteries? If they are 5+ on original battery, it's time for new ones. Subsequent replacement batteries don't last as long.

BMW have always been voltage sensitive, a weak battery can signal lots of other unrelated issues.