Same on my 428i. 1st and 2nd can be slightly notchy from cold. Something I have noticed on all BMW's I have driven.
For 1st and 2nd its easier if you fully depress the clutch or sometimes it doesn't engage properly, the other gears are much easier. Also the gearbox doesn't like to be rushed.
My problem is I been used to driving a 5 speed for so long, I forget I have the 6th gear.