Custom functions on group-head-cell in Row Grouping are Failing in React

Problem:
After trying to run this studio demo on my local react project, I am seeing the "render_score_title" rather than the content returned from the function. The cell is just rendering the function name which is passed as a string and I am wondering if we need to pass any other attributes on the table to support this.

Solution:
In this React demo, the custom function on the column will render a basic group-head-cell title. Please use it for reference. After downloading the compressed file, extract and install dependencies with npm install in the root folder. Run npm start to see the application in the browser.