Gantt Chart 2.2.3 - Rounded or sharp corners on task bars (error?)

I'm using a Gantt chart to track ownership of assets. All of the below have the same commencement date, and a few months different in end date. As you can see, the start points of the bars are not rendering consistently and some are defaulting to sharp instead of rounded corners. Is this a bug, or is there a setting I can't find to fix this? Thanks