When selecting the Month View of the Gantt, unexpected blank space appears and the cell headers are not properly aligned.
To reproduce the problem, open this demo:
https://demos.telerik.com/kendo-ui/gantt/basic-usage
And Click Edit in Kendo UI Dojo:
https://dojo.telerik.com/OparoYUJ
Zoom out the browser so the Gantt has some larger Width and you will notice the blank space + misaligned headers:
The same issue can be observed in the Getting article: https://docs.telerik.com/kendo-ui/controls/gantt/get-started