I am having issues with certain font awesome icons not showing up in Sydney. For example, the fa-couch icon does not display at all. Installing the latest version of the font awesome plugin did not solve my problem.
That icon appeared in Font Awesome 5.0.9, but Sydney theme includes Font Awesome 4.7.0. That’s why you can’t use it yet, unfortunately.
Font Awesome 5 is a big update, so its update in Sydney might take some time. Please feel free to ask any other questions that you might have.
Kind Regards, Roman.