I've had this happen a couple of times now....lats time was just a few hours ago....
Whilst driving, the rear-door/boot "pops", and the warning Icon on the IP (Door open) appears, its just a case of stopping, opening the boot, & re-closing....but its donw it a couple (Maybe three) times since I got it last Sept. Its never OPEN, just on the latch, as it were.

I guess I should make a note & get them to sort this out when it goes in for its 1st service (together with the squeeky gear-shift)

Anyone else had this? '57 FL2 GS
Sumatra Blk, Tints, Winterpack, Dodgylooking TowBar, roof rails, Front & Rear LED Indicators, Clear Side repeaters(Led), LED Rear Position/Brake lights, Additional Power-point in the boot & Brighter luggage Illumination fitted

sounds like a faulty switch in the boot handle or a loose connection Former Mod/Member, with the most post & Chicken George Arch nemesis

Try turning the rubber bumpers on the door in a little to allow the boot to shut easier.