Not sure if this started in 1.30 as I didn't notice it until today. Is returnStdOut no longer supported? I didn't find any mention anywhere of it being removed. 

Scripts still run of course but nothing is printed out from the script run even if the Powershell script has write statements.

Now getting this warning - 
WARNING: Unknown parameter(s) found for class type 'org.jenkinsci.plugins.workflow.steps.durable_task.PowershellScriptStep': returnStdOut