So let me cut your suffering, had similar issue with Bmw north shore and Brian Jessel.
They did some warranty work on suspension, couple weeks after,there was some clonking noise.Went back they couldn't find what's wrong.
Got recommendation for Nixon automotive, went there, setup appointment, they found right away what was it, Bmw dealership didn't retorque to proper specs or at all.That was just one of many thing wrong with "authorized services"
Save yourself of unnecessary hassle, time and money.
https://nixonautomotive.com/