Hi,
1. To solve this issue
Go to the Appearance -> Editor -> inc/custom-functions.php
at line no. 590 find the below code
return '<a href="'.$link.'" target="_blank" class="'.$icon.'" title="'.$icon.'"></a>';
and change it with this code
return '<a href="'.$link.'" target="_blank" class="'.$icon.'"></a>';
2. Please add full URL of your social media profile like below
[social icon="fab fa-facebook-f" link="https://www.facebook.com/gracewordpressthemes/"]
Regards
Grace Themes