Apertura font glyphs not working in Typekit

I'm using the Apertura font and am now trying to get the glyph ï to work in a website.

When you test this character in Typekit, it shows only the top dots but not the i shape. In Illustrator this glyph works perfectly fine.

I selected the option to include all characters in the Typekit project, without result.

What's wrong here?