widget not working

I’ve tried everything and the shortcode doesn’t work on my site.

I’ve uninstalled plugins, deleted plugins, deactivated plugins, etc. but it doesn’t work on this site: https://capitalirishfilmfestival.org/schedule/

I themed this site, so I’m guessing I’m missing something.

However, I also themed this site, and the plugin/shortcode works just fine on it : solasnua.org/nothing/

could you help me out please.

https://www.ads-software.com/plugins/artfully-widget/