PowerShell script running as different user in Windows Task Scheduler

I am trying to configure a PowerShell script which will run in Windows Task Scheduler for multiple service accounts. I found a way to run the PowerShell script with a given user via the 2nd answer in this link Running PowerShell as another user, and launching a script.

For reference this is the PowerShell snippet:

$username = 'userA'
$password = 'passwordA'

$securePassword = ConvertTo-SecureString $password -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential $username, $securePassword
Start-Process C:\BatchPath\MyBatch.bat -Credential $credential

Now in Windows Task Scheduler I configure the job and in the execution I have it setup to run Powershell.exe with additional arguments '-ExecutionPolicy Bypass C:\ScriptPath\Script.ps1'. If the user for this task scheduler entry is configured as userA then it works. If I configure the task scheduler entry on userB then it fails. Both userA and userB are administrators on the machine.

In the second scenario I would expect that the script file would be started by userB but then the PowerShell Start-Process would force the batch file to be run as userA. From watching Task Manager I don't see the job within the batch file started.

This example is a bit superficial but in the final form of the PowerShell script it would be running different batch files with different service accounts.

Copyright Notice：Content Author:「Jeff Fol」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/46676391/powershell-script-running-as-different-user-in-windows-task-scheduler