Trucks not respecting area-assignments

Last I checked trucks didnt go and deliver outside their assigned areas.
I noticed today on my save that they do.
v0.7.9 (b495)
Attached pic of a truck I have assigned to a solo area. green is path to a dump location outside it's assignment

Does that storage structure have a logistic route connected
to the mine controll tower that allows vehicles to dump there?

Because that (logistic routes allowing to bypass zone boundaries) should be allowed.

I don’t want trucks to wander around the map just because their current zone is full. Let the storage fill up and give me a warning. I need the trucks doing the work in their assigned zone, not wandering around the map.

Right so the truck is assigned to the storage, the storage is set to dump. There is no other export/import on the storage but the truck seems to go dump outside its zone when there is nothing in it's zone to do anymore. I am pretty sure this behaviour has changed at some point.

I am finding it happens even when export routes are set from the storages.