Add Working Item via plan view bizarre behavior

I have two project areas each with slightly different process configurations.

I am trying to add new Work Items from a Plan by right clicking the parent Work Item  Add Work Item.  This works fine on all Work Item types in project area 1.  In project area 2 this only works on a subset of Work Item types.  For example I cannot do this on our high level Work Item types of Epic and Feature but I can on all other Work Item types.  The option of Add Work Item just does not come up.

I am wondering what setting or permission or what I have missed.

Thanks