I have always found that some fonts do not appear in Lightroom, but never realized that this may also affect Book and Print modules differently.
I find that in my Windows-10 (File Explorer) any font marked as- "Restricted licence" will not appear in the Book module.
I used to think that only 'true-type' fonts would work in Lightroom, but the fonts shown in the C:\Windows\Fonts folder (in Detail view) do not indicate if they are true-type or not. But I do see "Font embeddability" as in my screen-clip.
The fonts that are "Installable" and "Editable" do show in the Book module for me.
We will need someone with more understanding to fully explain why fonts show, or not.