No output in PowerShell Plugin of Jenkins

Question

I'm using the Jenkins Plugin (not pipeline) Windows Powershell for my scripts. Everything is fine, if the script is written directly into the Command-Window. But for some more complex operations I'm using a .ps1-File located on my SCM, since all that code is too confusing for that tiny Command-Window. The script is triggered properly, but I don't get any output (Write-Host) of that file.

How I run the script:

cd MyScripts
if ($env.CONDITION -eq "condition") {
    powershell -File .\myScript.ps1 $env.HOST
}

Is there any clue I'm missing?