I have it set as the SelectedGroup in the XML file and I have the other tab's visibility set to Collapsed, but it still opens on the 2nd tab (Characteristics) instead of the first.

Expose API to control the card view items in DataBound scenario. In this case, we can expose API to update the order and visibility of the cardview items in the DataBound scenario.

Please refer to the attached gif file illustrating better the layout problems with RadCardView. The DataSource is set at design time to the Employees table. Using the designer the default card view layout template is customized. After running the application, you will notice that the collapsed state of the groups is not consistently preserved and the card view items overlap with each other.