@ CW, good call.
IVM aka "Integrated Supply Module"
It cracks me up how they keep the German abbreviation but translate the part name to English. My favorite is Drive Away Protection is of course EWS.
BMW 12-52-7-510-638 Integrated Supply Module
https://www.amazon.com/dp/B00NQFCUEA..._RtQvEb1WMQJVW
That part can cause symptoms like described it regulates the voltage for most of the brain boxes of the car.