OP - this is exactly the same thing happening in my 21 LCI. This has nothing with the sequence of shutting down. There is definitely something going on in the rear and it is not consistently happening every time but more so than not.
I'll ask my service advisor during the next check in.
This never happened in my 2019 pre-LCI. I posted it earlier in the year after having the car for a month or so - see my third point:
https://f90.bimmerpost.com/forums/sh....php?t=1834085