The CSS entries for the jacket are absent, viz:
The one on the left is from the book I attached to post 11, the one of the right is what Odyssee posted. I can't find the styles used by the jacket, cbj_author, cbj_banner etc. No idea how, why - other than some css cleaner deleted them.
@Odyssee - try the Polish Book tool (select book and press 'P'), use the
Remove a previously inserted book jacket option, and then run it again and use the
Add/replace metadata as a "book jacket" page option
BR