I have a website with Hebrew text which contains niqqud and cantillation (both are sets of diacritic marks).
In order to ensure the proper display of these marks, I embedded a font on my site. Using FontForge, I modified the original font, adding two stylistic sets (ss01 and ss02).
The original font displays correctly; however, on Apple devices (Safari on Mac and iOS), the new font is causing problems.
When I embed the new version of the font, the text suddenly displays as if none of the font features are enabled (despite the fact that mark, ccmp, and mkmk should be enabled by default, and that I enabled them explicitly in the CSS).
On Windows, in all browsers, this font is displaying appropriately.
An example of the incorrect behavior:
I tried changing font formats from woff to ttf, but nothing changed. At the moment, I placed a CSS Hack embedding the old version instead of the new version in all Safari browsers, but I would really like to be able to use my new Stylistic Sets in Safari as well.
A test site without the CSS Hack can be found here; the text with the issues is in the right side of the page.