I have another solution for this problem that might apply to some of you.
After I created my power shell (xyz.ps1) script, I opened it in notepad for subsequent editing. Hence Windows made an association between my xyz.ps1 file with notepad.exe and Scheduler was trying to run my power shell script (xyz.ps1) with notepad.exe in the background instead of executing it in Powershell. I found this problem by paying close attention to "Display all running tasks" section in the scheduler, which showed that notepad.exe was being used to run the xyz.ps1 script. To verify this, I right clicked on my xyz.ps1 file in windows explorer, went to "Properties", and it showed Notepad against the "Opens With" section. Then I changed the "Opens With" to %SystemRoot%\SysWOW64\WindowsPowerShell\v1.0\powershell.exe. This did the trick. Now the scheduler would execute my xyz.ps1 using powershell.exe and gave me the desired results.
To locate your powershell.exe, refer to this article: https://www.powershelladmin.com/wiki/PowerShell_Executables_File_System_Locations