BMW 120d N47: Rough Idle Cold Start. Any ideas?

Hi, I have a BMW 120d (N47). After starting the car on a cold start there are fluctuations in the revs for over 2 minutes (rough idle). Once the car has been driven for a while, stopped and restarted then there is no issue with the rough idling after start up.
I have seen this can occur with this model. Any suggestions for potential fixes to rectify this issue?
I have plugged a scanner into the car but I see no codes which provide any help.
Thanks in advance.
#bmw #120d #n47 #roughidle #startup #car #diy #help