Cannot override role access per page in view

I have a tabbed view with four page tabs.
For the four tabs, Page settings: Access is set to Role | Multiple roles (internal and sales partner).
I add a fifth tab and set Access to Role: Internal (only) and make sure that "This page (override)" is selected before I click Apply (this display).
However, when I do this, the access option is set on all tabs in the page. So I am unable to add a tab which can only be seen internally.
I have perused the help but can see no description of this fact. Is it a known issue, or is there some embedded logic to this that I do not grasp?
I can supply exported view if needed.
Thanks!