@WilliamXing Your help request contains a link to a web page that has font awesome font examples on it. When I originally clicked on the link (thereby downloading the page) the font qlphs showes as rectangles because I had the uBlock Origin ad blocker running. When I disabled it and reloaded the page the glyphs appeared properly. My suggestion was that maybe you, like I did, had an ad blocker running.
Here is what the page looks like when I have the ad blocker running (red shield in upper right corner). Click the screenshot to see a bigger version.