I'm seeing custom fonts on your site right now. There are a few things I'll offer.
1. Browsers now-a-days, to appear faster than they are, rely far more heavily on cached files. That means when you change a font, it might not show up for you till after you clear your browser cache and then reload the site.
2. Most ISPs use invisible proxy servers to, again, make things seem faster they are, and if those proxy servers are slow to update, it might be a few hours before you see the custom font. It all depends on how heavily they rely on caching and how often they update their cached files.
3. You are working over the internet and their are many, many things in between you and the wordpress servers and the font servers, and if a font server is overloaded, or is experiencing issues, or if the internet between your computer and the font servers is clogged up or experiencing issues, things may time out and you will not see your custom fonts.