What other factors might affect numbering in a book?

I have inherited a book that had 6 chapters and I've added a 7th chapter at the front.  I've gone into the Numbering Properties set up and set it so that the first chapter says "Chapter #1" and the rest say "Continue numbering from Previous File in Book."  However, when I ask it to update the numbering, I still get the first two labeled as Module 1 and then it continues with Module 3 labeled as 2, Module 4 as 3, etc.

Any suggestions as what else might be playing a role in this?

Thank you!