Steps to reproduce

• Create a pipeline using the Jenkinsfile example below
• Open the activity tab
• Run the pipeline
• Open the run in a new window
• When you see the pipeline marked as unstable on the run screen, refresh the activity tab
• The pipeline looks like it has finished
  See the screencast

What you should see
The run should always be shown as running if it is still executing

Example

node {
    stage ("stage 1") {
        sh 'ping -c 3 localhost'
    }
    stage ("stage 2 marked as unstable") {
        currentBuild.result = 'UNSTABLE';
        sh 'ping -c 10 localhost'
    }
    stage ("stage 2 wait ") {
        sh 'ping -c 10 localhost'
    }
}