Solved Kunena Index page displays only 1 category after installing Blue Eagle Template

Using Joomla 3.8.2, PHP 7.0.98, Kunena 5.0.12.

Previously -- Kunena Index page displayed all of my Section Headings.
Menu Item Link: index.php?option=com_kunena&view=category&layout=list&catid=0

Now, after installing the Kunena Blue Eagle template (which may be unrelated to the issue)
- the Kunena index page displays only my last category.
Menu Item Link: index.php?option=com_kunena&view=category&layout=list

Notice that now there is no "&catid=0" after "list" like there used to be. But, that does not seem to affect anything.

Desired Goal: I would like to get the index page to display my Category Section Headings. (The sub categories should be collapsed because there are so many categories that it would become confusing.)

Thank you for any suggestions.

That was very helpful. I was able to use the category display settings that you referenced to solve my problem.