title: Multibranch pipeline job not showing open pull requests
body: <p>I have configured a multibranch pipeline job in Jenkins linked to our GitHub repo which is working nicely, feeding back the status of checks to the pull request in our GitHub so we know if the branch is good for merging in.</p>
  
  <p>What I don't see are any open pull requests listed against the Job in Jenkins:</p>
  
  <p><a href="https://i.stack.imgur.com/LgZ9p.png" rel="noreferrer"><img src="https://i.stack.imgur.com/LgZ9p.png" alt="enter image description here"></a></p>
  
  <p>We also have the Blue Ocean plugin in installed and no PR's are shown there either.</p>
  
  <p>Anyone know why this is the case? Am I missing another plugin\config?</p>