IcoMoon has made some changes in their structure that require dash at the end of a class prefix in IcoMoon preference settings.
Here is what happens if dash is not present at the end of class –
IcoMoon Preferences Setting

How It Looks In The Backend

What’s Wrong In The Code Behind, Why It Doesn’t Work

And when there is a dash at the end of class, see how things work smoothly –
IcoMoon Preferences Setting

How It Looks In The Backend

How Is The Correct Code
