How to change task duration when greyed out

I have various tasks, however my first task “research” seems to think my whole project is under this task. It is therefore greyed out and I cannot amend the duration. It has the start and end dates of the project but its only supposed to last a few days. How can I change this?
As you can see, research goes across the whole project

my other tasks only last the duration of the main task

https://docs.ganttproject.biz/user/scheduler/index.html#summary-task