JUnit XML system-out shows logs from all threads

Question

I have a JUnit5 integration test project where I'm running the test classes in parallel. My problem is that my log messages are being mixed together in the junit XML report generated after the test class finishes executing. This makes it difficult to debug the root cause of a failure because sometimes the xml containing a failed test won't even have a system-out section for the failed test because another xml report grabbed them already.

This xml report is showing the system-out from 3 out of 4 threads. How do I get this so that it is only showing the correct thread in the xml report?

<testcase name="beforeEachFailure" classname="tests.BeforeEachTests" time="32.962">
    <failure type="java.lang.AssertionError">
        <![CDATA[
        java.lang.AssertionError
        at tests.BeforeEachTests.beforeEach(BeforeEachTests.java:19)
        ]]>
    </failure>
    <system-out>
        <![CDATA[
        10:45:23.227 [Thread-0] INFO  StaticUtil - Sleep for 3s
        10:45:23.228 [Thread-0] INFO  BeforeAllTests - continue doing a thing
        10:45:26.228 [Thread-1] INFO  StaticUtil - Sleep for 3s
        10:45:29.228 [Thread-1] INFO  StaticUtil - Sleep for 3s
        10:45:32.229 [Thread-1] INFO  StaticUtil - Sleep for 3s
        10:45:32.229 [Thread-1] INFO  TestTests - half the things done
        10:45:35.230 [Thread-2] INFO  StaticUtil - Sleep for 3s
        10:45:38.231 [Thread-2] INFO  StaticUtil - Sleep for 3s
        ]]>
    </system-out>
</testcase>

Configuration for maven-surefire-plugin:

<plugins>
    <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-surefire-plugin</artifactId>
        <version>3.0.0-M4</version>
        <configuration>
            <statelessTestsetReporter implementation="org.apache.maven.plugin.surefire.extensions.junit5.JUnit5Xml30StatelessReporter">
                <version>3.0</version>
                <usePhrasedTestCaseMethodName>true</usePhrasedTestCaseMethodName>
            </statelessTestsetReporter>
            <consoleOutputReporter implementation="org.apache.maven.plugin.surefire.extensions.junit5.JUnit5ConsoleOutputReporter">
                <encoding>UTF-8</encoding>
            </consoleOutputReporter>
            <statelessTestsetInfoReporter implementation="org.apache.maven.plugin.surefire.extensions.junit5.JUnit5StatelessTestsetInfoReporter">
                <usePhrasedClassNameInTestCaseSummary>true</usePhrasedClassNameInTestCaseSummary>
            </statelessTestsetInfoReporter>
            <redirectTestOutputToFile>true</redirectTestOutputToFile>
            <reportsDirectory>${basedir}/target/surefire-reports</reportsDirectory>
            <includes>
                <include>**/*Test*.java</include>
            </includes>
            <properties>
                <configurationParameters>
                    junit.jupiter.execution.parallel.enabled = true
                    junit.jupiter.execution.parallel.mode.default = same_thread
                    junit.jupiter.execution.parallel.mode.classes.default = concurrent
                    junit.jupiter.execution.parallel.config.strategy = fixed
                    junit.jupiter.execution.parallel.config.fixed.parallelism = 4
                </configurationParameters>
            </properties>
        </configuration>
    </plugin>
</plugins>

log4j2 configuration:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration>
    <Appenders>
        <Console name="Console">
            <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %c{1} - %msg%n"/>
        </Console>
    </Appenders>
    <Loggers>
        <Root level="trace">
            <AppenderRef ref="Console"/>
        </Root>
    </Loggers>
</Configuration>