Book Page Numbering Problems

Hi All, hoping someone can help.

So I have come back to finish editing my hubby's book after a hiatus of a few months, I think there has been at least one update in the intervening time. I had been making the corrections I had recently worked on then looked down and suddenly realised that the page numbers were all wrong.

Attached is a screen shot to demonstrate.

The Book panel and the styles panel show the correct number, which in this example is page 19, but the number on the actual document in question is "1".

All the files before this are numbered correctly, but all the chapters after this start at "1" , and not the number given in the book panel.

Any help would be much appreciated. I will contine in the meantime to follow up on a few discussions I've found here, but so far, everything suggested is about the updating of number in the book panel. 

Thanks In Advance

[I hit the "How to" Topic as none of the others seem to be applicable to my issue, unless there's tech lingo for my issue here that I dont know of! Evenutally it'll be pirnt and EPUB, but I'm not there yet. ]