Its not broken, the space divider separates topic and longer time periods

Why is there a time divider, if the time is shown on the right side anyway?

It breaks the flow, for the benefit of showing the time twice?

Look this feature is great for a lot of comments and activities over time. While you scrolling it improves your orientation in time because your eyes is focused primarily on the left side and change focus on the right for orientation is overwhelming. Time on the left is time of group of activities and time on the right is specific time of each activity and you can view its detail on hover.
e.g.
https://report.bistudio.com/issues/DZG-85
https://report.bistudio.com/issues/ARGF-222