special characters vanishing from headlines

I have a strange problem I am unable to troubleshoot: Special characters (like ? ? è à é ó) vanish from my headlines while the page is being rendered. I see the characters while the page loads, then the font suddenly changes and they disappear. You can see for yourself here:

https://www.drinkhacker.com/2010/01/19/test-%C2%A2nneaeo/

This is only in headlines, not body text.

I am using the theme LightWord 1.9.9.4

Any advice appreciated!