Update issues

I updated version 8.x-1.12 to 8.x-1.14. But Drupal still keeps warning me that I have an update for Drupal8 W3CSS Theme 8.x-1.12.

Now, i am using a sub theme that shows up in the appearance list as My_dzinelabs 8.x-1.12 (default theme).

So, although the base theme is listed as 8.x-1.14 it seems that somehow I get a warning that the sub theme is still 8.x-1.12. I.o.w., even updating the base theme, this does not reflect as far as the sub theme goes. Is this a theme problem or a Drupal thing?