Hi,
Sorry for the issues you are having.
Not sure why this is not working. I have a test site I run for the Events Calendar and my customizations are in my Child theme for Genesis and everything is working.
Let’s start with the easy steps and see if we can find the answer.
Can you please verify the child theme is active.(simple I know, but just in case something happened there)
What is your Parent Theme? Does another Parent/Child Theme Combo Work?
Let me know and we can go from there is have you test for conflicts and see if that finds something.
Thanks