What Should I Do When a PDF with Selectable Text Was Not Extracted Correctly?

Hi, What parser are you using?
If you have not used LlamaParse , I would highly suggest that you give it a try!
https://docs.llamaindex.ai/en/stable/llama_cloud/llama_parse/

What is the problem? Each page of a pdf by default is treated as an separeted doc, you need to make a custom pdf reader if your problem is: chunk starts at a bottom of a page and ends in the top of another page then this solution could work