You should not notice too many differences (except the irrelevant results disappearing). In your case it will make it more precise.
When using the regular engine, the shortcodes and filters are not executed and indexed, it simply searches the posts database table as it is. I'm guessing that the Divi builder is using a filter or a shortcode to create a widgetized area, and does not store the actual widget contents in the post content, in the database.
In other words, the index table engine is used to get the words from the final output (visual output) as it's represented on the front-end, while the regular engine simply searches the “raw” data within the wordpress posts database table. The raw post content and the visual post content are different – as the visual content is already post-processed. Because the regular engine searches the unfiltered (unprocessed) data, the contents from the widget are not there yet.Best,
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