Perspective shows wrong project due date

I created a perspective that is supposed to filter tasks that are either with one tag or within project inside certain folders, the perspective should display by projects grouped by due date and sorted by project:

The problem is that some projects with no due date are listed as due within a week:

Even if they have no due date at all! #bug ?.

When is the Flagged Task due? it may be inheriting the due date from that.

The flagged task is not due.