Dependent role based dropdown view issue/bug

Hi,

Bit of an odd one this. 

We have a main status field and a sub status field. The status is the parent dropdown and determines what to show in the sub status (via studio).

The sub status is however role based. 

The bug is that a user who shouldn't be able to see an option in the child dropdown can see it (but can't select it) and then it disappears when another option is selected e.g.

Parent A should show child options 1,2,3,4.

Parent B should show child options 5,6,7.

The child dropdown is role based so the user in question should not be able to see option 4 in this case. 

When the user selects Parent option A they should only see 1,2,3 however when they first view the menu they can see option 4. It's only when the user opens the menu and clicks an option they have permission to does that option disappear. 

Is there anyway to resolve this? I've attempted way to re-render the field but that doesn't appear to have worked.

Thanks,

Steve