This sometimes happens...
After I've inked and digitized a page I'm just not happy with the panel layout. Perhaps it's the time spent staring at the page without concentrating on pencils, on structure, but purely the flow of story. It happened a few times in Book One. There were several pages I went back and redrew/added/subtracted panels.
And it's already happened for Book Two. I was not happy with the first two panels of page 18, how they worked together, what they framed, and how they progressed the "chase" or "stake out".
The new page is on top. The original below. I think the addition of the new panels adds more suspense and adventure to the page!