Conditional step in post step of Maven Project run despite of result of build step

Not expected behavior when run Maven project job in Jenkins and set Conditional step(single) to execute shell when build status SUCCESS.
When Maven build step fail( for example because of failing to parse POMs) conditional step *will be executed and it *not should be.
Seems like Conditional step can not retrieve Maven build status.
After adding System Groovy Script to Maven post step, Job build status is null and in Post-Build Action is FAIL when one of Maven build steps failing and is SUCCESS when all Maven steps are successful