Hello!
Until now, the issue appears (or disappears 
) with Cantarell:
Exporting a slide from Impress, all other fonts used in the slide are printed excepting those texts in Cantarell.
Changing the PDF version gave the same result.
I thought it was a issue with Impress, but Writer do the same, despite a font cache update and two LO-still re-installations, one from the cache and the other a fresh download after removing the LO package from /pkg (procastinating 
). Reinstalling the font gave the same issue.
No big deal but curious behaviour…