Not had that. Are you pulling the switch long enough? In my experience you need to hold it up for a half second or more. A flick of the switch may not work.
I've noticed mine does this but I think I just don't hold it for long enough.
Howver It's annoying me slightly and I might get BMW to look at it when it eventually goes in for service.
Maybe get it checked as I don't need to hold mine at all, as long as it's fully pulled/pushed to the extent of the lever (I.e. not just flicked) I don't need to hold it at all?
Yep, so long as its not flicked up and down, it should work fine, just hold the button up or down for a short period until you hear it engage. its a noisy old bird so unless you're at an airport when you press it, you'll hear it.
Maybe get it checked as I don't need to hold mine at all, as long as it's fully pulled/pushed to the extent of the lever (I.e. not just flicked) I don't need to hold it at all?