Thanks! this ebay failure right out the box was it! With one OEM HPFP from leebmann24 here in Germany no failure and I'm back on track with full power. No default reset procedure necessary as viewed in one video (15min idle run with unplugged fuel vent valve cable).
I tried a 130€ from Frankfurt-Oder and a 360€ near Frankfurt-Main from ebay. Both as rebuilt but crap. They had no QR code as the OEM. Apparently ebay HPFPs are mechanically rebuilt but apparently not hydraulically rebuilt and electronically reset as per BMW standards.