Rear hatch lock adjustment.

[mrpj]

I realise my 2014 Yaris is a French built U.K. version but -
The rear hatch has always, from new, been difficult to close fully. i.e. it's always needed a hard slam to engage the lock mechanism properly. I meant to say something to the supplying dealer when it was in for service last March, but forgot!
However, on all the cars I've ever owned there has always been some adjustment with either the striker or lock itself, or both. This doesn't appear to be the case with the Yaris.
I slackened off the 2 x 10mm bolts holding the lock, no movement. I then removed the boot/trunk trim to access the striker, marked it's position using a pencil, slackened off the 2 x T40 screws and again, no movement.
Does anyone know if there is an adjustment for this or not as I seem to have found?