Hello,
to me it seems the 2020 R3 update breaks a little on (some) custom views. I have a custom view adopted from your documentation at https://docs.telerik.com/kendo-ui/controls/scheduling/gantt/how-to/creating-custom-view. If I open this in the Dojo, the tasks don't line up with the table (see attached file). If I change back to 2020 R2 SP1 release from the dropdown at the top left (and cleanup the stylesheet reference), the tasks once again lineup with the table.
Also the line this.list.header.find("tr").height(height + "em"); that seems to be used to adjust the tasks <> tables gives an error of Uncaught TypeError: Cannot read property 'header' of undefined when I update to the latest release and am running the Gantt in a node.js app. Where can I do the adjusting in a custom view when I update to the latest release?