Age old issue with a twist

[Davol70]

Hi all,
I'm new on here guys so bear with.
I have just purchased an e70 x5 msport 40d and loving it so far apart from the issue that has been mentioned in here a thousand times probably!........the electronic parking brake not working and constant annoying warning light/chimes. But there is a twist to mine! I have tried all the usual, reset with 5 seconds down and up etc. And removing the fuse but no joy. My twist which is really confusing is that when I'm in motion, if I pull up the brake switch the brakes actually come on and jolt the vehicle! But stationary absolutely nothing.
I had the 5 series f11 previously so no the sound when activating the parking break and not getting that at all!
Any ideas??
Much appreciated