Hi
Thanks for providing the info.
The pagebreak is applied to article content only, while the text you're referring to on Author Listing page is a custom field called 'About me' under 'User info' tab in user settings in backend of your site.
I guess that you want to hide the text under the pagebreak class you added, right?
I added new div tag with hideMe class and defined this custom css rule:
.author-lists .author-block .author-about-me .hideMe {
display: none;
}
to hide that text.

Kindly check.