Font-awesome some icons missing

Question

I'm going crazy with this issue. I want to show 8 icons on a page, but only 4 of them are showing up. I have looked up this for help, but I got nothing useful. I checked also on StackOverflow but didn't get anything useful either.

The full code is here.

And this is how I see the icons:

I get this in localhost and uploaded it to altervista. I get this with Chrome, Firefox and Vivaldi. I get this with local fa files and with the CDN. The icons that aren't visible are missing the :before but I don't know why. Can someone help me?

Answer 1

You are using icons (e.g. fa-thermometer-half or fa-free-code-camp), which were introduced in version 4.7. However in your website, version 4.6.3 of FontAwesome is included (see here). So, update your FontAwesome instance to the newest version to solve your problem.