Hi there,
this sounds like a problem with having the sidebar sticky and viewing the page on a smaller screen or with a high level of zoom
ie. there isn’t enough room to display it all whilst its sticky.
You can reduce the size of the content in a few ways:
1. Customizer > Layout > Sidebar and reduce the Padding.
2. Customuzer > Typography > Sidebar:
a. Reduce the Font sizes of Title and Content
b. Reduce the bottom margin on the Title
This should reduce the space they take up