Bullets and numbering keep changing start number to random values

[Blenderik]

I created a book and use the same text style for each file.
Every chapter starts with a chapter heading, which is the source for level 1 of my bullets and numbering.
Then there are sections (level 2) and figures (level 3).
So I want the 1. section of chapter 2 to read:
2.1 My Second Chapter
and the 3. figure in this chapter fig. 2-3
Which works using the 3 levels, setting the bullets and numbering to global and using the same style in each chapter. However when I close and re-open a chapter and go to the 1. occurrence of the 1. section it arbitrarily gets changed to something like
17.38 My Second Chapter
I just went throught the entire book to fix this, but once I close and re-open all chapters after the first are labeled wrong again. I can go back, search for the place where it says "Restart numbering now", manually put in the correct numbers again, the chapter updates, but gets messed up again after re-opening.