Kobo pop-up footnotes and h2

[repilo]

I have an EPUB 2 book with footnotes numbered 1 to 43 (all in exactly the same format), which I convert to kepub with Calibre and transfer to my Kobo Libra 2 via DropBox.
Footnotes 1 to 24 are displayed in popup window.
From 25 onwards, instead, it jumps to where the text of the note is located at the end of the book.

It is important to say - as you will see later - that each xhtml file has a unique h1 header, at the beginning, and several h2's intercalated throughout each file.
And the headers appear in the table of contents.

Although I don't know why this happens, I have managed to find where it happens.

The notes whose call links appear in a place before the h2 labeled as <h2 id=“sigil_toc_id_39”> are displayed (at least in my case) in popup window, not so those whose call link appears below said h2

• If I rebuild the table of contents with Sigil, but only “Up to level 1” (i.e. excluding the h2), then ALL the notes are displayed in popup window.
  
• IF I rebuild the table with “All” the headings
  THEN the problem returns, notes 25 and following no popup.
  
• IF I rebuild the table and uncheck the h2 mentioned above (it changes to <h2 class=“sigil_not_in_toc”>)
  THEN note 25 becomes popup, BUT note 26 and following does not.
  And I notice that the h2 after that has changed to id="sigil_toc_id_39”

I wish someone from Kobo would see this, but I doubt they would do anything about it.

[DNSB]

Perhaps instead of using header tags in your footnotes, you could use appropriately styled p tags?

And yes, Sigil's ToC build code builds the ToC based on the use of h1-h6 tags. That's the purpose of h tags given the common definition I've seen in multiple places is "the <h1> to <h6> tags are used to define HTML headings".

Personally, I use h1 tags for books in a multi-book omnibus, h2 for parts within a book, h3 for chapters & h4 for sections within a chapter. The only time I used h5 & h6 was in one textbook which was a (IMNSHO) dog's breakfast considering over 1,300 entries in the xhtml ToC file made it almost useless on most devices/apps that didn't support ToC collapsing.

[repilo]

Originally Posted by DNSB

Perhaps instead of using header tags in your footnotes, you could use appropriately styled p tags?

I don't quite understand what you mean. So I'm going to detail it a bit more.
File 07.xhtml:

<h1>Header</h1>

  <p>Text.<a id="rf24" href="notes.xhtml#nt24"><sup>[24]</sup></a></p>

<h2 id="sigil_toc_id_39">Header</h2>

  <p>Text.<a id="rf25" href="notes.xhtml#nt25"><sup>[25]</sup></a></p>

File notes.xhtml:

  <div class="nota">
    <p id="nt24"><sup>[24]</sup> Text. <a href="07.xhtml#rf24">&lt;&lt;</a></p>
  </div>

  <div class="nota">
    <p id="nt25"><sup>[25]</sup> Text. <a href="07.xhtml#rf25">&lt;&lt;</a></p>
  </div>

Footnote 24 (and previous footnotes) is shown in popup window; footnote 25 (and following footnotes) is not.
For some reason, only footnotes above <h2 id=“sigil_toc_id_39”> (at least in this particular case) are shown in popup.
If I move footnote 25 above said h2, then it shows in popup.
If I rebuild the table of contents only up to level 1 (i.e. not including h2), all footnotes are shown in popup.

[neclepsio]

I don't know if it can be useful, maybe I'm wasting your time. I did many tests for a book of my own in the past. I have the sensation that the offset in the file is somewhat important. So, what happens if you split notes.xml and move nt25 and following in a newly created notes2.xml?

[repilo]

Originally Posted by neclepsio

I don't know if it can be useful, maybe I'm wasting your time. I did many tests for a book of my own in the past. I have the sensation that the offset in the file is somewhat important. So, what happens if you split notes.xml and move nt25 and following in a newly created notes2.xml?

I did it, and the problem kept happening in the same place, at the same footnote.
Later I found out that it was related with the h2 headers, which seem to impose a certain limit with their id="sigil_toc_id_x".
If I remove the "id" from the h2 tags, the problem disappears.
It has nothing to do with the 4,000-character limit people mention because these footnotes are very short (no more than 2 lines each), and there are only 43 of them.