Hi,
The issue is coming from this script file, based on the console: https://multimed.pl/wp-content/themes/clinico/js/scripts.js?ver=1
The script file is from the current theme directory. It is probably because the theme isotope script is likely missing from that page. The search uses a different isotope scope, so it should not be related, the error message does not refer to any of the plugin script files either.