I've been told by more than one beta reader that there's a specific chapter where they went from "meh" on my book to really feeling invested. But that chapter is just past the halfway point. What I think people are responding to in that chapter --a deepening friendship between the main characters --has been built up through the first half of the book, so it isn't necessarily something I can solve by moving events around.
What might cause this specific pattern of reader response, and what are ways to address it? In a world where I could guarantee people would read my book, I would be OK with a slow build leading to a satisfying reader experience in the second half. Given, however, that you send the first few pages in your query, and that the modern audience demands instant gratification, it's clear that my book needs to engage people right from the very start.
To be clear, there's plenty of action in the opening of my book, but it takes time for the deeper, more emotionally resonant themes to develop. (Furthermore, as I highlighted in my other question, my character isn't initially very likeable.)