In the Assignment Center in grid view, there are 2 click points that have separate functions. One is the detail screen where the teacher can edit the assignment. The other is the screen where the teacher can add in grades for that assignment.
In some assignments, the title is hyperlinked and clicking the title of the assignment brings the teacher to the detail screen.
This is the link the teacher will click in order to access the detail screen:
User-added image

The title turns into a hyperlink if the assignment has downloads, links, long description, etc. If the assignment has any information that can't be shown in grid view, the title will be hyperlinked.

If a teacher clicks lower on the assignment with the hyperlink, they will be brought to the edit grades screen to add/edit grades for that assignment.

Not working as described above?  Try checking to for erroneous HTML that may be interfering with the link creation in the title. Just edit the assignment and choose the HTML button in the editor tools of the title section. You should just see your text there but if you see things like <span or <div tags trying removing them.