No numbers in OS X preview

Does anyone have an idea why my Mac OS X (10.11.2) Finder window doesn’t show any numbers in for my OpenType font file? I have the figure sets lnum, pnum, tnum and onum in my font.

Yes. It sometimes does, it sometimes does not. No one really knows what determines the display of the figures. I have had cases, where some font family members showed the figures, and others did not. Generally, Apple poorly documents things that are font-related. And this is just another example, I am afraid.

Ok, I see. Good to know that it doesn’t seem to be further of a problem.
Thank you!