Free FullFrame – no slider since WP 5.6.1.

Dear Catch team, I've been using FullFrame theme for more than 5 years and had this situation (slider not appearing) before when WP changed fully few years ago. Last time deactivating plug in's and activating them back one by one worked for me. But now with this version 5.6.1 no. Demo works ok. I've checked all settings in Featured Slider. And refreshed and updated all pages set up for slider with no results. Could you please advise and help. site: http://www.akademijasvjesnogzivljenja.com/