When working with Plans, the time line I have configured to show dependencies however, I see only "relates to" dependency types, I have blockers types specified in some stories but they do not appear in the timeline. Why can't I see dependencies other than "relates to"?
Even when I try to add a dependency on the timeline view, the only type of dependency offered in the drop down is "relates to". Why aren't the other dependency types shown here?

Note: there is only one project in this plan/type, and all dates are specified in the sprints and stories inherit dates from the sprints.
Thanks,
Tom