Since you made your second Master based on the first one, you will have to override the items to edit them. (shift-command-click)
Thanks so much! That fixed it!
Thanks for prompt response! That fixed it! Or as I wrote in my notes:
To create a new Master based on Master A
Master Options (based on Master A)
Override All Master Page Items
Don't override all of them! Only those on which you have to make changes.
Work with layers!
The reason for basing one master on another is that they need to have the same content on both masters, with other non-shared content on one or more. It makes sense most times to start with a Master page that contains only the shared content.