building block <$chapnum> not showing the correct chapter number in the list of figures

I am trying to modify the ListofFiguresTpl.fm template that I use in my DITA project in order to change the numbering of the figures, appearing in the List of figures part.

The reason is that the default numbering, as it is, restarts the figure numbers in each chapter to 1 then adds up the numbers throughout the chapter. However, in the list of figures, appearing in the end of the book, the numbers are accumulating. Consequently for the same figure you get two different numbers in the chapter and in the LOF. So I decided to change the numbering by adding the chapter number first then the figure number within that chapter. I first modified the ChapterOutputTpl.fm using the paragraph designer: f:Figure <$chapnum>.<n+>:\t. This works fine. However when I do the same in the ListofFiguresTpl.fm, the chapter number is always 1.