Categories not showing

I recently set up a new site with the Olympic Blue theme. My client has since added categories but they don’t show up in the sidebar.

The site is here:

https://productivitymuse.com/pm

The code for the categories is:

<?php wp_list_cats('optioncount=1&hierarchical=1'); ?>

Changing the optioncount to 0 took away the parenthetic number to the right. Changing hierarchical to 0 didn’t seem to do anything.

I tried swapping in code from another site that works fine, but it didn’t help. I haven’t seen anything in the admin that allows any choice to show or hide categories.

Thanks for any help!