Ok, having spent a good portion of last weekend scouring forums and the internet, I give up!
Car was last serviced ~Oct 2019, ~26k miles, now at 28k~ and INSP light appeared last Thursday. Right, I thought, this *doesn't* actually need a service, just a case of resetting the inspection message.
Have managed to clear it (ignition off, press & hold RESET button, ignition on, INSP disappears, release button, press again, start car...etc) , well, temporarily...start the car up...all fine, no ping, no INSP. Job done, or so I thought...next day...PING + INSP message re-appears.
Repeated the reset procedure...still won't permanently clear...
Any ideas much welcomed!