Hi,
Thanks for the accesss and sorry for the delayed response.
You are using a third party template there and the template has overrides for the addon named function box. We do not have any addon named like this: https://prnt.sc/4wiGGmchYMJM, but we have feature box addon instead: https://prnt.sc/aCzxQ2pxxLsi
I guess, the feature box addon is the overrided addon with Function box there: https://prnt.sc/Mw069-gJWkAd
I have renamed that site.php file and your site is working fine. You may contact your template provider about adjusting the template overrides to match the latest SP Page Builder version there as well.
Best Regards