Different results when running Java program inside Intellij

Intellij IDEA 2021.2 (Community Edition) under Linux Mint 20.2

This problem started with the Runtime.getRuntime().exec() method always returning "error=2, unknown file" for some executables under /usr/bin. For example, I can getRuntime().exec( "/usr/bin/ls") just fine, but I can't exec /usr/bin/lp without errors. File permissions, ownership, and file type are the same for both programs.

After some debugging, I found that this problem also affected the java File object. When the following program is run from Intellij IDE, the file is not found. But if compiled and run externally, it is.

What's going on here?

Program Listing: Note: The Intellij program had a package declaration, the external version doesn't.
============

import java.io.File;

public class FileUnknownError
{
    static void checkFile( String fName)
    {
        File f = new File( fName);
        System.out.printf( "Checking File:          '%s'\n", fName);
        System.out.printf( "         Exists:        '%b'\n", f.exists());
        System.out.printf( "         Is File:       '%b'\n", f.isFile());
        System.out.printf( "         Is Absolute:   '%b'\n", f.isAbsolute());
        System.out.printf( "         Can Read:      '%b'\n", f.canRead());
        System.out.printf( "         Can Write:     '%b'\n", f.canWrite());
        System.out.printf( "         Can Execute:   '%b'\n", f.canExecute());
    }

    public static void main( String[] args)
            throws Throwable
    {
        String fName = "/usr/bin/lp";
        checkFile( fName);
    }
}

Output from Intellij:
==============

Checking File:          '/usr/bin/lp'
         Exists:        'false'
         Is File:       'false'
         Is Absolute:   'true'
         Can Read:      'false'
         Can Write:     'false'
         Can Execute:   'false'

Output from external running
======================

Checking File:          '/usr/bin/lp'
         Exists:        'true'
         Is File:       'true'
         Is Absolute:   'true'
         Can Read:      'true'
         Can Write:     'false'
         Can Execute:   'true'