I hope you are well today and thank you for your question.
The shortcode content is not displayed in the search results as it may break the markup of search results.
You can develop custom code to display shortcode content in the search results by using the is_description_markup hook of the plugin declared in the below plugin file in the function description_markup on line number 542
/add-search-to-menu/public/class-is-ajax.php
If you are not a developer then you can consider hiring a developer to develop it for you. You can hire a developer from any freelance site or WordPress agency.
You can also consider us to develop it for you using the form https://ivorysearch.com/custom-work/
Best regards,
Ivory Search Support