When adding a font to the application from data on Mac then it may not pick up the right one for use later

When adding a font to the application from data on Mac then it may not pick up the right one for use later. In this case the font added has the same family but two different traits, one contains the normal font and one contains the bold version. When it is added as a file it works fine, but when they are added via the data (or via a resource file) then it will not pick up the bold one correctly.

With the attached example this can be reproduced, however the fonts are not available as they are not redistributable.