I often encounter a 1 line offset between the list and the chart.
Can be fixed by changing to ressource and back or restarting the application.
I still see this. Here’s a screenschot that shows the misplaced elements:
Yes, it happens sometimes, sorry. There is an existing issue in the tracker: https://github.com/bardsoftware/ganttproject/issues/1798
We don’t know the reasons yet, sorry. As a simple workaround, resizing the window and dragging the chart should help.