Do you have all headings in the same story as the main text? If not, you have to join them in a single story.
Not sure what that means?
Do you have separate text frames for each heading? They should be connected to create ToC as expected. Can you show me page 23 with all objects and characters visible?
Add Frame Break at 1 (after "Sadistic"), click on a blue square (2), click on the frame with "Sadistic" (3):
And now connect these two frames into one story.
Your two frames didn't need to be threaded (though it won't hurt). If the TOC appears out of order as it did in your very first screen shot, try cutting the chapter title frame and the paste it back in place (Edit > Cut, Edit > Paste in Place). The stacking order will make a difference in unthreaded frames.
Also note that while a frame break is an option, in a long document a better alternative is to use assign Start Paragraph: In Next Frame to your Chapter Title style so that you can use a style to control the position instead of remembering to manually add a character. It's in Keep Options.
Since you have gone ahead and threaded the frames, did you remember to update the TOC in the InDesign document prior to re-exporting to EPUB?
Frames not threaded. No frame break character. Correct navigational TOC in the fixed-layout EPUB file.
Ok, Thanks Barb!