Pipeline with Matrix: Robot results display seems wrong

Hi all.

I have created a pipeline with a simple matrix configuration with one axis and 2 items within.
The job runs robot framework tests on each item and publish results using the robot plugin.
It appears that even though 2 reports are apparently shown, only the last generated report is displayed.
The environment is :

  • Linux Debian Buster
  • RobotFramework 5.0
  • Python 3.7.3
  • Jenkins 2.332.1
  • Matrix Project Version 758.v7a_ea_491852f3
  • Robot Framework plugin Version 3.1.0

My pipeline looks like :

@Library('CiLib') _

pipeline{
	agent { label 'JenkinsDocker1' }
	environment {
           ......
	}
	stages{
	    stage('Clone Repo') {
	        steps{
                    echo "Cloning Repo"
                } 
	    }
           stage('Running Tests'){
             matrix {
                axes {
                    axis {
                        name configMode'
                        values 'standalone', 'primary'
                    }
                }
                stages {
            		stage('Run Tests') {
            			steps {
            		            make("test-${configMode}")
            			}
            		}
                        // Robot Results are stored in testsResults/${configMode} 
            		stage('Publish Results') {
            			steps {
                                  robot(
                                    logFileName: "log.html",
                                    outputFileName: "output.xml",
                                    outputPath: "testReports/${configMode}",
                                    passThreshold: 100.0,
                                    reportFileName: 'report.html',
                                    overwriteXAxisLabel: "${configMode}"
                                  )
            		    }
                  }
            }
    	}
        stage('Archive Results') {
		steps{
			  archiveArtifacts(
				 artifacts: "testReports/**", // relative path from the current dir
				 fingerprint: true,
				 onlyIfSuccessful: false
			 )
		}	
       }
    }
}