Preferences: Common Options:Structure Detection
controls splitting
But good luck with
adjusting that for your issue
Why?
Because there are coders out there who
still seem to style with H tags.
Both the lines have H tags in offending files. Thus they get split
I happen to use the Editor to Simply change all but the First (what should be in the TOC) use to a P tag.
I see no difference (assumes they have a Class= or Style ).