And one more thing to try… you can redirect output streams (everything, including warning and error streams) to a file to see if there’s any other info added there.
To do this, go back to the Actions tab of the Task Scheduler. Doublecheck the Program/script points to powershell.exe and then under the Add arguments (optional) section, you can specify both the path to the script and an output file as follows.
Program/Script:
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
Add arguments:
C:\Users\jeffl\Scripts\refresh.ps1 *> C:\Users\jeffl\Scripts\refresh.log
The *> will redirect all output stream types to the specified file.
Once your task runs, look for the refresh.log output file and see if there are any errors mentioned in the file.