Gradle + SpringBoot: :integrationTest not executed in build task

I have problem with executing integration test like part on build task.

Input:

• Java 11
• Gradle 6.5.1
• integration Tests Spock(groovy)
• Spring Boot 2.2.x

    Project structure:
    |_build.gradle
    |_src
        |_integration[integrationTest]
        |   |_groovy
        |   |_resources
        |_test[unitTest]
        |_main[code]
    
    

In build.gradle file I do have:

build.dependsOn(integrationTest)
compileJava.dependsOn(processResources)
compileGroovy.dependsOn(processResources)

test {
    useJUnitPlatform()
}

integrationTest {
    useJUnitPlatform()
}

When running ./gradlew integrationTest all fine. But when using ./gradlew clean build --debug all build successfully but integration test not triggered. In the logs I can find this:

[class org.gradle...TaskExecutionLogger] > Task :integrationTest NO-SOURCE
[org...DefaultBuildOperationExecutor] Build operation 'Task :integrationTest' started
[org.gradle...ResolveTaskExecutionModeExecuter] Putting task artifact state for task ':integrationTest' into context took 0.0 secs.
[org.gradle...DirectoryFileTree] file or directory '/Users/.../build/classes/java/integrationTest', not found
[org.gradle...DirectoryFileTree] file or directory '/Users/.../build/classes/groovy/integrationTest', not found
[org.gradle...DefaultEmptySourceTaskSkipper] Skipping task ':integrationTest' as it has no source files and no previous output files.
[org.gradle...ResolveTaskExecutionModeExecuter] Removed task artifact state for task ':integrationTest' from context.
[org.gradle...DefaultBuildOperationExecutor] Completing Build operation 'Task :integrationTest'
[org.gradle...DefaultBuildOperationExecutor] Build operation 'Task :integrationTest' completed