Content posts are not coming in two column

On my homepage or category page where we have multiple posts in boxes, its not coming properly in two columns, the right side column is empt.

I am using latest pinboard theme version with child theme that doesn’t have anything major, just some CSS changes for layout and tracking codes etc.

URL: https://www.journaldev.com or https://www.journaldev.com/dev/java

I noticed this issue around 2 days back and I haven’t changed anything recently.