Realm Not Working with Packaged Electron App

I've started the Realm-provided realm-electron-advanced-quickstart found here.

Everything works fine when running in dev, but when I package this with electron-builder, the app does not work. I moved createWindow() to the top of the app.whenReady() function so I could see the debugger, and it showed the following message:

Failed to open realm: Error: illegal operation on a directory
    at run (renderer.js:26)
    at renderer.js:39

Line 26 is

const realm = new Realm(config);

I suspect this is some sort of path/permissions issue with the .realm file.

In main.js, I changed the path in the realm config to

path.join(app.getPath("home"),"my.realm")

But I could not do so on renderer.js.

I would appreciate any ideas or examples of how this has been implemented before.

I'm running Node v14.15.4.