Hello. Thank you for contacting the Toolset support.
Can you please tell me where exactly you added the custom shortcode and on what part of the problem URL you shared under what title.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin and FTP) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.
I understand but as I shared there is some issue due to theme or any other plugin you use. It it either caching or theme issue. To ensure its theme issue, you will have to run a test with another theme.
If it works with default theme then you will have to get in touch with your theme author.