Problem with function get_the_author()

Hi. I have the plugin “Post author” that allows me to show above or after the article “written by..” and the author is displayed as a link. At first, when I clicked the link, it showed me what I wanted from the beginning, which is to see all the posts from a certain author. When I click that author link the page with “Articles written by…” still displays, but the author name doesn’t display anymore. All of a sudden.