Bug with the sliding hidden object in Axure PR9

I am trying to show/hide a dynamic panel (default state is hidden) of menu and sub-menu navigation under a hamburger icon. Further, the sub-menu can be expanded and collapsed with a chevron to the right of main menu.

The issue is, as I click on the chevron to collapse or expand the sub-menus (after the drawer of menu come out on click on hamburger icon) the options (sub-menu items) disappears. Surprisingly, this does not happen at all if the default state of this dynamic panel is not hidden on the stage!

I don’t understand if this is due to any bug with the tool or I’m not doing it right! Any pointer would be helpful.