hi @dankar79,
We have used the most popular sticky Script for the sidebar. The script works just after tracking the instant height of the sidebar. Here the problem is that the external plugin/script that you used for the last three widget is not giving the height instantly. The timing of rendering those elements has affect the height so the sidebar is overlapped by the featured posts. If you refresh the browser again then its working perfectly. If you still want your site to work well with those plugin/scripts then we suggest you to make the sidebar regular rather than Sticky.
If you don’t want to make the sidebar sticky then Add below custom CSS code in Appearance > Customize > Additional CSS .
.widget-area .sticky-wrapper,
.widget-area .sticky-wrapper.is-sticky {
height: auto !important;
}
.widget-area .sticky-wrapper .sticky-sidebar,
.widget-area .sticky-wrapper.is-sticky .sticky-sidebar {
width: 100% !important;
position: relative !important;
top: auto !important;
}
.
.