Cannot delete task

I have just started using Ganttproject a couple of days ago, and am currently trying to create a new Gantt based on the first one I finalized. The new Gantt is very similar to the first one, but I have to ged rid of a few tasks, and unfortunately some of them just won’t disappear when I select “delete task”. They are not linked to any other task so I cannot figure out why. Can anyone provide some insight on this matter?

Please share the project file and provide a reproducible scenario.

I fixed it in the meantime (can’t remember how though…was not intuitive)