Start-ADTProcess not timing out - set to 150 minutes

I am running a powershell script inside a Start-ADTProcess and I've set the timeout for 150 minutes, but it carried on for 264 minutes.

        $result = $null
        $StartTime = Get-Date


        $result = Start-ADTProcess -FilePath "$PSHOME\powershell.exe" `
            -ArgumentList "-file `"C:\test.ps1`"" `
            -Timeout ([TimeSpan]::FromMinutes(150)) `
            -TimeoutAction SilentlyContinue `
            -NoTerminateOnTimeout `
            -IgnoreExitCodes '*' `
            -CreateNoWindow `
            -PassThru


        if ($null -eq $result) {
            Write-ADTLogEntry -Message "test still running after 150 minutes, moving on."
        } else {
            $Duration = (Get-Date) - $StartTime
            Write-ADTLogEntry -Message "test completed with exit code: $($result.ExitCode) | Duration: $([math]::Round($Duration.TotalMinutes, 1)) minutes."
            if ($result.StdOut) {
                Write-ADTLogEntry -Message "test output:`n$($result.StdOut)"
            }
        }

In the log file it stays the following
[Install] :: test completed with exit code: 0 | Duration: 264 minutes.

Screenshot of the time it started and the time it finished:
image.png (265×63)

Any ideas what's gone wrong? Is it the switches in the Start-ADTProcess?