Hi James,
Thank you for all the details, I resolved the issue for you.
The product tabs custom post type is a bit misleading, as it is not actually a link to the product itself, it is parsed along with the product. I will make sure to disable that within the upcoming release, as it caused confusion before.
Since you gave access to the back-end, I made the adjusments to the search to get that information from the product tabs for you:
1. I have enabled the index table engine and configured it to index the products: https://i.imgur.com/9pljdsM.png
2. Then on the search options, I enabled it, and selected only the products: https://i.imgur.com/4LZRPnq.png
Now, searching the data from the product tabs will return the corresponding product as the results. I hope this helps!