Mine did this the other day, latch wasn't in latched position... I sprayed some lube in the latch mechanism and she's working great again... nobody wants their junk in the truck falling out :biggrin2:
I will check mine with a pull before setting off on a journey since it opened up while going down the road with a few bags of dog food in back when my latch decided it needed some lube... luckily no spilled bags.