After you paste the name in the text box, hit the space bar and then delete the space. The Heroku interface doesn’t detect the paste action as having text in the input box until you add another character.
"After you paste the name in the text box, hit the space bar and then delete the space. The Heroku interface doesn’t detect the paste action as having text in the input box until you add another character."
THIS! I just experienced the same thing. Good info.