I am having the same issue with the arrows in the Testimonial section as reported here: Testimonial Section Issues.
Instead of displaying as arrows, I got squares in the section at the bottom of www.alvarvelasco.com
I have tried the solution given there (adding to the custom CSS this piece of code:
@import “https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css”). But it is not working. Any other idea?