I'm using JUnitResultsArchive to record test results, and I'm seeing a weird bug where there are failures reported but the build is not marked unstable.

This is via Jenkins pipeline, and immediately after the step, I'm echoing the build result:

step([$class: 'JUnitResultArchiver', testResults: 'build/xunit.xml'])
echo ">>> BUILD RESULT ${currentBuild.result}"

I can confirm that a test failed in that step, and the result printed is ">>> BUILD RESULT null"

This doesn't always happen - in some other runs, the result is UNSTABLE as expected.