Unable to link in Contents menu

I’m trying to draft a simple RAB app which is the beginning of a Lectionary. I would like to have different “books” that are each one month in the Lectionary, each day of the month a chapter in the book, and the user should be able to select the current month in the Contents Menu. Here is the starting section of one of my current draft SFM files:

\id Lect06-25
\h Lectures de juin 2025

\mt1 Lectures de juin 2025

\c 1
\s1 1 JUIN
\s2 DIMANCHE
\s2 LA PENTECÔTE
\p 1re lect.: Ac 2, 1-11
\p Ps: 103, 1ab et 24ac, 29bc-30, 31 et 34
\p 2e lect.: 1 Co 12, 3b-7.12-13
\p Évangile: Jn 20, 19-23 ou Jn 15, 26-27; 16, 12-15

\c 2
\s1 2 JUIN
\s2 LUNDI
\p 1re lect.: Gn 3, 9-15.20 ou Ac 2, 14a.36-41
\p Ps: 86, 1-2, 3 et 5, 6-7
\p Évangile: Jn 19, 25-34

I can add this book to the app and then add a Contents Menu item, but I can’t assign that menu item to a Target in the book. I can select the book, but the Chapter menu is blank:

If I click OK with a blank Chapter, then open the link item again, the Book field is also empty again. If I build the app like this, the Contents Menu item is there, but clicking on it doesn’t go anywhere (it sort of just highlights the line in gray), so there is NO WAY to get to the text of the book!

If I add a Scripture book to the app, along with a Contents Menu item that points to it, then that link in the menu works, and I can go to that book. Once I’m in that book, I can use the book dropdown to go to my Lectionary book, and I can read it just fine. Or I can go to the end of the Scripture book and swipe to go to the next chapter to get to my book. But I can’t use the Contents Menu.

So I assume that there is something missing in my SFM file, to make the Contents Menu find the chapter numbers? I’ve tried a number of things (adding verse numbers, adding a Book Group, etc.) but can’t seem to find the magic formula. If anyone wants to try playing with it, here is a test RAB project folder:
Lectionnaire Arabe.zip (1.1 MB)

Thanks for any help you can provide!
Jeff

Since “real” Scripture books were working fine, I changed the \id of my book to \id REV, deleted the old book and added the new version in. Now the Contents menu works fine!

So now I can select the item in the contents menu and it will go to “REV” chapter 1.

But surely there must be a way to point to a book in the app from the contents menu without having to pretend that the book is a book of the Bible? (I have a book for each month of the year, and potentially several years, so eventually I might run out of books!) When you add books to a collection in SAB, it states that you can add SFM, DOCX, Bloom books… Are target links from the contents menu broken for all of these books (since none of these will be marked as Bible books in their \id)?

I’d appreciate a solution to this problem.
Jeff