Hi there!
Better Search Replace Support Team here, Thanks for reaching out with your query we would be happy to assist
It’s possible that it’s a cache issue. If you have any caching plugins installed, kindly try clearing any cache on your site and see if that resolves the issue.
If you are using a theme builder, perhaps the data is saved in a different table. Please try including all tables in your search/replace process. You can start with a dry run, to see if the text is picked up in a different table.
If the issue persists, could you please send us the exact search and replace term you’re using for further investigation. If those are links/URLs, we would recommend checking how those are stored exactly in database. Sometimes plugins or themes can store URLs differently than WordPress core does, which can result in Better Search Replace missing those URLs.
You could use a tool like phpMyAdmin to take a look at the URLs in MySQL and see what the proper search term should be.