This happens because you are trying to set your active item on the ownerCt (which is a TabPanel) with a newly created component (aes.views.SearchList).
For this reason, the TabPanel will add the new card as Tab inside the TabPanel.
Are you sure you want set the activeItem of your TabPanel instead of your application viewport which (maybe) has a "card" layout?
Hope this helps.
Sencha Inc Andrea Cammarata, Solutions Engineer
CEO at SIMACS