Are these FabricUI components still supported and can i use them? The icons works randomly

I'm investing and trying out some of these components in my web part (classic page)

The Persona Card

https://developer.microsoft.com/en-us/fabric-js/components/persona/persona 

Ref below

https://static2.sharepointonline.com/files/fabric/office-ui-fabric-js/1.4.0/css/fabric.min.css

https://static2.sharepointonline.com/files/fabric/office-ui-fabric-js/1.4.0/css/fabric.components.min.css

https://static2.sharepointonline.com/files/fabric/office-ui-fabric-js/1.4.0/js/fabric.min.js

Any ideas why the icons works randomly. ..sometimes they appear sometimes it doesn't

 Some icons work some dont. For example <i class="ms-Icon ms-Icon--Vacation"></i> this doesn't work but this does <i class="ms-Icon ms-Icon--Phone"></i>

I'm getting the icons ref from here https://codepen.io/MistaTwist/pen/BoNLEG and what to know if my fabric UI js and css references are the correct ones

Thanks in advance