title: Design Automation doesn't end work properly with 2019 revit
body: <p>I have some unexpected behavior.
  When I work with the 2020 engine and 2018 everything correct.
  But when I use the same instruction for the 2019 engine, the job doesn't close even after call OnShutdown method.
  I don't have an uploading phase for this job, so after OnShutdown call, it should end.
  But for some reason job closes only after manual canceling.
  <a href="https://i.stack.imgur.com/GEZe8.png" rel="nofollow noreferrer">design automation report</a></p>
  <p>In this sample, I wait 2 minutes before cancel. But also was 10 and 20 minutes of waiting.</p>