Task view headers: generic, not per project?

I am working on a few projects plans simultaneously. Some plans I would like to view where a column in task view is a week, and others where a column is a month.

What I now experience is that when I change the task view header (using header customization) in one project file, it also changes that view in my other project.
What am I doing wrong here?


I believe that changes in Preferences are global (affect all projects.

To achieve what you want, you need to adjust the headers in each project via the drop-down or by dragging the separators in the header.

Hope that makes sense