Table of Contents is one chapter off

Compiling the book using the eBook settings, with a few tweaks from me, is coming out fine. But it seems the table of contents is one chapter behind.

Clicking on Chapter 1 goes to the Front Matter.

Clicking on Chapter 4 goes to Chapter 3.

Etc. Any idea of what this is?

Hmm I’ll leave this up, but just saw this thread:

I have a similiar issue, and using something besides Kindle Previewer 3 fixed the issue.