If you run the pipeline below, click on it while it is running , you won't be able to click on the non focussed parallel branch (see video)

I did a production deployment this morning upgrading from blueocean 1.3.4 -> 1.4.0 and immediately received developer reports that they were unable to reliably switch between branch views by clicking on nodes in the pipeline display graph.  This doesn't seem to be occurring with builds that have completed but it is critical usability problem as it prevents developers from monitoring builds in progress (which in our env, is often hours).

 Sample: 

pipeline {
agent any
stages {


stage("parallely") {
parallel {
stage('left') {
steps {
sh 'ping -c 100 www.apple.com' 
}

}

stage('right') {
steps {
sh 'ping -c 100 www.apple.com' 
}

}

}
}
}

}