External process will not launch powershell

We use an external monitor system (i.e. external to PS) that can take certain actions when the monitor fails its test condition. In this particular monitor, I have a batch file that it launches when it fails. The contents of the batch file is below:

set hh=%time:~0,2%
if “%time:~0,1%”==" " set hh=0%hh:~1,1%
set yymmdd=%date:~10,4%%date:~4,2%%date:~7,2%
set yymmdd_hhmmss=%date:~10,4%%date:~4,2%%date:~7,2%-%hh%%time:~3,2%%time:~6,2%
echo %yymmdd_hhmmss% Restarting Service >> d:\scripts\restart_hubtst2b_wrapper.log
START %SystemRoot%\system32\WindowsPowerShell\v1.0\powershell.exe -File D:\Scripts\Restart-Service.ps1

I know the external system is launch the BAT because I see the log I’m generating in the batch. However, I don’t see the log that should be generated from the PS script (Restart-Service.ps1).

I’m stumped because the batch file works fine when I run it manually while logged in with the same service account that the monitoring system runs as. The contents of the PS is below. Does anyone have any idea why this batch file would work okay when logged interactively, but fails when the service tries to run it?

Set-StrictMode -Version latest

Function Write-Log
    Param ([string]$msgString)

    (Get-Date -format "yyyy-MM-dd HH.mm.ss.fff") + " :$msgString" | tee -FilePath "D:\Scripts\$logname" -Append

Function InitializeLog {
    Param ([string]$logPrefixString)

    $logname =  $logPrefixString + "-" + (Get-Date -Format "yyyyMMdd") + ".log"
    return $logname

$logname = InitializeLog “serverName_RestartWrapper”
$s = get-service -ComputerName serverName -Include “ServiceName”
Write-Log “INFO: Attempting to stop $($s.name) on serverName”
Write-Log “INFO: Service $($s.name) was successfully stopped on serverName”
Write-Log “INFO: Attempting to start $($s.name) on serverName”
Write-Log “INFO: Service $($s.name) was successfully started on serverName”

Does the service have permissions to run the batch file and read/write the appropriate data?
Does the service have permissions to interact with the system in the way you want

Like I said, the batch and PowerShell script work just fine when I’m logged in interactively with the same credentials as the monitoring service. This same pattern works when we use VBScript instead of PowerShell. Do you have any specific permissions for me to check as I’m unaware of any special PowerShell related permissions?