Sprints with same name are automatically closed

[Fernanda Jacques Garcia]

When a sprint of a project is closed, all sprints that have the same name are also closed, even they are from different projects.

[Nic Brough -Adaptavist-]

There are no "sprints of the same name", it's all one sprint.  Sprints don't belong to projects either, they're cross project.  I suspect what you're seeing is that "sprint X" is appearing on more than one board and maybe in more than one project because it includes issues that are in different boards/projects.

A sprint can span more than one project, if multiple projects are included in the board on which the sprint was created. A sprint is visible on all boards that contain issues belonging to the sprint.

[Fernanda Jacques Garcia]

In this case they are different sprints in different projects and different boards. 

[Nic Brough -Adaptavist-]

Projects are irrelevant, the point is that it's one sprint.

[Fernanda Jacques Garcia]

I renamed one of the sprints and the other was not renamed. Therefore they are different sprints.