This is a plugin conflict, and it’s not easily fixable.
The first “Authors” submenu item is an existing item. Apparently, PublishPress Authors normally explicitly removes the item (in publishpress-authors/src/modules/multiple-authors/multiple-authors.php, lines #447 to #456 in version 4.1.2). However, when Admin Menu Editor is active, the custom admin menu configuration is already done at that point, so that attempt to modify the admin menu has no effect.
Usually, I would add the item to the internal blacklist that AME uses to hide menu items like this. That won’t work in this case because the top-level “Authors” menu has the same slug as the first “Authors” submenu item: hiding the submenu item would also hide the top-level menu.
I recommend hiding the menu item using the “Hide without preventing access” button in the menu editor toolbar (a rectangle with a dashed border).
Appreciate that @whiteshadow
I’ll pass it to Authors developer. We can mark it as closed for now