Facebook shows Published by ACME?

The "Published by..." is not displayed to your Facebook Page visitors, only to administrators ("admin") of the Page.

In the Facebook admin view of a Page the source of the post is shown, for example "Published by ACME". Facebook automatically adds this meta data in the admin view.

Please see here on how to view a Page as a visitor or view the page in a Private/Incognito tab in your browser.