The impression I get is as follows.
(a) In SD there is an aside container.
(b) The contents of that aside container are making it stretch downwards beyond the bottom of the screen.
(c) The result is that the whole page will scroll down, but has nothing to show further down apart from the aside container.
(d) What is wanted is for the scrolling to be of the aside container only.
If that is so, I would deal with it as follows in SD.
1. I would set the height of the aside container to 100vh.
2. For that aside container I would go to the Styles panel, Layout section, Position heading and set the box marked Overflow to Scroll.
Purely to demonstrate what I mean, I attach an example page using Frameworkless. The principles used can, of course, be applied to the various frameworks as well.
If the above is not the kind of effect that is wanted, I suggest that further details of the problem be provided so that someone can help. I'm afraid that my help must be limited to the above. I am not qualified to help with PHP.
Frank