My MB has the occasional "glitch". Sometimes it sneaks in an extra wipe when the wipers are on intermittent, or the cruise control turns itself off in standby. It went a little crazy a few weeks ago - I even had the engine cut out briefly. I was about to reset the
ECU (disconnect the battery) when it came right, and has been fine so far this month.
Maybe I disturbed something when replacing the cabin air filter just before Christmas?