title: Create Pull Request Button is disabled
body: <p>I would like to make a pull request from my fork repo to the upstream repository.</p>
  
  <p>As always I was following these steps <a href="https://help.github.com/en/articles/creating-a-pull-request-from-a-fork" rel="noreferrer">here</a> from <strong>the guidance from Github.</strong></p>
  
  <p>But this time I can not make a pull request, as the button is <em>disabled.</em></p>
  
  <p>The branches can be automatically merged.</p>
  
  <p>I do have changes in my forked repo and I can see commits made.
  Base repo and head repo are indicated correctly.</p>