You’re seeing that ‘not found’ box, because fontawesome is not fully loaded.
Use browser developer tools to find errors like this.
In Chrome, go to website, press F12 (MAC: Command+Option+J), Developer Tools will open.
Click the Console tab, there you can see the client-side errors.
When i do this for your site i see the following fontawesome error:
Access to Font at
‘http://www.thedetailpro.com/wp-content/plugins/elementor/assets/lib/font-awesome/fonts/fontawesome-webfont.woff2?v=4.7.0‘
from origin ‘http://thedetailpro.com‘ has been blocked by CORS policy:
No ‘Access-Control-Allow-Origin’ header is present on the requested
resource. Origin ‘http://thedetailpro.com‘ is therefore not allowed
access.
This error is new to me, it’s a server setup error.
A quick Google search, see this.
Regards, Bjorn
p.s. don’t forget to charge your client for this F** up 😉