Spurioius blank pages after chapter numbering

Hi, great software tks.
Using for years though now having issues. After compile for mobi, I find that 25% of the chapters have a blank page after the chapter heading and chapter text appears then on the next page as if there was a page break after chapter headings.
Okay, just checked and in PDF different chapters appear to have blank pages after the chapter numbers.
Thanks
RR
Anyone have any idea why?

There are three places where page breaks can be inserted:

  1. In the Separators compile option pane. There are some combinations of settings there that could produce the effect you describe. The default here, by the way, is to insert a page break before folders that follow text files (the fourth section in the list).
  2. The “Page Break Before” checkbox. This is a per-item setting, but instead of going through each one by one, you can get a quick list in the Contents compile option pane. It could be the first scene following the chapter has this flag set. I’m leaning toward that since you mention the result is not consistent but only happens roughly a quarter of the time, whereas Separators should at least produce a consistent malfunction.
  3. Lastly you can insert page breaks right into the text editor as well. To hunt for them, use Format/Options/Show Invisibles and check the text files around the spurious breaks to see if there are any blue lines to delete.