All ps scripts fail to run

I have ARM 2020.2.5 installed on Windows 2016 server running Powershell 3.1 withe Set-Execution at Unrestricted. I have multiple ps scripts which run OK from the Powershell ISE but not from within ARM.

When I look at the command line displayed in the ARM Configuration, Scripts screen after assigning a script to an action, copy to clipboard and run it, ISE displays an error, "unsupported inputformat (none)". The full command line is in the form "powershell.exe -inputformat none -file c:\.......\filename.ps1".

Any ideas on how I fix this?