I've had this issue attended to by AB KL, Ingress and AB Glenmarie without any success.
The squeaking normally returns after a few days. AB Glenmarie claimed to have swapped the front discs around as an attempt to fix the problem, without any success.
Their SA told me it would be brought up to BMW MY if still no improvement after the swap. So just wanted to get feedback from you guys here before i go down that road.