Scrolling different frame doesn't work as expected there is a bug

I am working on a prototype. Which has two frames next to each other in the main body left side frame has scrollable content and the right side frame will be fixed once the left side content hits its frame bottom both the left and the right frames have to scroll up to reveal the footer.
But the scroll tops after the left side content fixed scrolling I had to manually move the cursor to the footer to scroll the entire body.

You can find the Link in the sample prototype here.

What am I doing wrong? or is there a better workflow. Please someone help me. It would mean a world to me. Thanks a mile