title: on prem Azure DevOps Server 2020- PRs cancelling in-process Build Validation builds
body: <p>We have an &quot;on prem&quot; Azure DevOps Server 2020.  For several of our branches, we have a branch policy requiring a &quot;Build Validation&quot; gated check-in build.  We have a build definition with one build agent for this.</p>
  <p>Our issue is that if someone submits a new Pull Request and another person has a Build Validation build going from another PR, the first build is automatically cancelled mid process and the new PR's build starts.  This is very frustrating of course- and require some management of PR builds which should not be needed.</p>
  <p>Does anyone know how to stop this behavior of a PR cancelling any in process builds?</p>
  <p>Many thanks!</p>