If you share a link to your store (preview link if password-protected) it will be easier to diagnose. Most probably, your font does not have these characters. In this case, browser will use a fallback font to render them.
So, check the font you're using whether it actually contains those symbols.
Yep, looks like the font does not have those symbols -- see the diagnostics at right bottom corner of the image. 20 glyphs in Karla and 2 glyphs in Helvetica.