Elementor updated their FontAwesome version 4.xx to 5.xx In this case sometimes you will see some icons like social media icons, carousel arrow icons will not display properly. 

For this situation, Elementor released an option to fix it very easily.

To fix it please go to WordPress Dashboard > Elementor > Settings > Advanced > Load Font Awesome 4 Support > Yes.

For SVG and large icon issues please go to WordPress Dashboard > Elementor > Settings > Features > Inline Font Icons > Inactive.