Favicon Not Showing
Sometimes you might find that your uploaded favicon (the little icon that shows in your browser bar) is showing while logged in to your WordPress dashboard, but not while you are viewing your live site.
This is usually a case of your browser cache not refreshing the favicon. This is a common issue, as can be seen in this WordPress forum post here.
The site icon feature is actually just the standard WordPress functionality, not something theme specific. If you want to try to dive deeper, there are a few solutions posted in this thread such as a plugin like this, or a force favicon refresh like this.
Also, some users have had success with these plugins: