can't change leader start position (sometimes)

when attaching a leader note to an object, I generally want the leader to attach to the top line of text in the note.

In the property manager for notes, you can sometimes adjust this attach point and other times you can't. I don't see

any rhyme or reason for this inconsistency. Can anyone shed some light on this?

(images attached for clarity)

thanks

SolidworksDrawings And Detailing