Bamboo Artifactory Plugin ArrayIndexOutOfBoundsException

[ropi2016]

Since we upgraded to Bamboo 8.1.3 and Bamboo Artifactory Plugin 3.2.8 we are getting the following exception in tasks of type 'org.jfrog.bamboo.bamboo-artifactory-plugin:maven3Task'.

[main] ERROR org.apache.maven.cli.MavenCli - Internal error: java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1 -> [Help 1]
org.apache.maven.InternalErrorException: Internal error: java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:120)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:957)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 1 out of bounds for length 1
    at org.jfrog.build.extractor.BuildInfoExtractorUtils.addPropsFromCommandSystemProp (BuildInfoExtractorUtils.java:320)
    at org.jfrog.build.extractor.BuildInfoExtractorUtils.mergePropertiesWithSystemAndPropertyFile (BuildInfoExtractorUtils.java:69)
    at org.jfrog.build.extractor.maven.BuildInfoRecorderLifecycleParticipant.getConfiguration (BuildInfoRecorderLifecycleParticipant.java:77)
    at org.jfrog.build.extractor.maven.BuildInfoRecorderLifecycleParticipant.afterProjectsRead (BuildInfoRecorderLifecycleParticipant.java:47)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:264)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:957)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:566)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)

We have used so far the Bamboo Variables artifactory.override.deployer.username and artifactory.override.deployer.password. That doesn't seem to work anymore.
If we select 'Provide username and password' in the drop-down list 'Override Credentials', the error no longer occurs.