The airbag control module which sits below the centre console certainly does some strange things when it gets wet - have you accidentally had the rood down during a downpour of late? If so, this could well be the problem. See here...
https://z4-forum.com/forum/viewtopic.php?f=3&t=105068
and here... https://z4-forum.com/forum/viewtopic.php?f=3&t=37521&start=30
and here... https://z4-forum.com/forum/viewtopic.php?f=3&t=36300&hilit=airbag+control