Sticky box not working

Design help Layout & Design
1

Hi, was hoping someone might help me with probably a really simple issue.

I’m a complete beginner and just getting to grips with Wefblow and with Positioning.

Why isn’t the box title ‘Get a free guide for modern interior design.’ Sticky in the below example?

https://preview.webflow.com/preview/new-30ca45?utm_medium=preview_link&utm_source=designer&utm_content=new-30ca45&preview=3318a66ff485be149f6ef9296837ef07&workflow=preview

Thank you!