I sent you a DM about this as well and did some follow-up testing since. I can confirm a compilation bug was introduced in Build 16142 and up. It’s not surprising that no one has caught it up until now, but it seems pretty nasty.
Specifically, I think the tweaks to page layout to address crashes may have affected compilation in that some lines at the top of some pages are simply lost. From my testing and that of my beta folks, it looks like it’s either one or two lines. In total my project went from 425 pages to 419. I didn’t even notice this, but my beta readers have reported back disjointed text throughout the book.
I had them provide specific places, then tracked down when my last “good” PDF was compiled. It was done using build 16093. Every PDF created from that point on, has been missing the same text at the same places in the page.
I saved all the various builds we used last week to track down the crash bugs, so loaded the project with each one and checked the PDFs. As mentioned above, starting with Build 16142, the content is lost.
I will try and DM you some screen shots and can resend my project to you if you guys have already deleted it. If not, you could do a compile with Build 16093 and the latest and compare the first two lines on pages 2, 5, 12, 13, 16, 17, 18, and 19. That seems to be the pattern, when the bug bites it snips off one or two lines at the top of a page.
Seems I was wrong and some others have noticed this as well. Here’s an associated thread: