Mine as well! I have soft close. It is only when weather is humid/rainy. It doesn't get hot here so often ;-)
Both my F10 535i and F11 530d (non-soft close) did not have this issue.
Current: MY2014 F10 535d (daily), MY2013 Porsche 981 Boxster S manual (fun)
Retired: MY 2011 F11 530d (temp), MY2010 F10 535i, MY1987 BMW E30 325i (fun), MY1974 BMW E3 2500 (fun) (and more..)