Currently, that is a documentation bug. The intention was to hide it everywhere, but I see the point in hiding only on the single page.
Nothing can be changed, however, until the next release of Weaver Xtreme (and none is planned soon), and this, as a checkbox, is not solvable via CSS.
You could, however, add this Custom CSS (you know where!) to hide on just single page (but don’t check the hide box):
.single-post #author-info {display:none;}
At this point, I will probably change the wording on the option, and keep this alternative for hiding the author bio on one place or the other.