Thank you for your reply and for checking the website nethgato!
The problem we are facing is that we are unable to highlight the code when we are selecting the it.
This gif shows what I mean.
First, the regular text highlights as normal when selecting it to copy-&-paste.
However, the code inside the Gist does not highlight in the same manner.
We are able to copy & paste but it is not a great user experience.
Thank you for checking our code and glad to hear we are doing it correctly.
Is this a style updating from GitHub or is this a conflict with Zendesk?
Thank you for your time.