Article Category not loaded in Blog Post Filtering

I aspected that while typing the name of a article category, a list of them appear. Instead nothing appear, except a “no data” message.
On another site, with same release of colibri and WP, the list is displayed.
Thank for the support

• This topic was modified 2 years, 2 months ago by imapm.

The page I need help with: [log in to see the link]