Agree with the advice above, assuming you haven't gone beserk scrubbing degreaser into your hot after a run frame (!) have you asked the dealer to explain why MucOff, which is widely used by all motorcyclists in the UK including other BMW owners, has caused the problem on your particular bike as you would assume they would be snowed under with warranty claims from other S1000 owners if that was the case? Clearly that isn't the case, so there must be more to the problem which you'd appreciate their help in getting to the bottom of as you love the bike, will want to buy future bikes from them etc etc..