WebViewer document.getMetadata() - metadata is all coming back as undefined

I’m loading a simple PDF document that has metadata (Title, Creator, etc.) into PDF.js Express Viewer.

I want to use the document.getMetadata() function to extract it after loading. My code executes, but the metadata all comes back as undefined.

My code:

        path: "/_content/pdfjsexpress",
        initialDoc: myUrl
).then((instance) => {
    instance.Core.documentViewer.addEventListener(instance.UI.Events.DOCUMENT_LOADED, () => {
        instance.Core.documentViewer.getDocument().getMetadata().then((e) => {

Console.log result is:

created: undefined,
creator: undefined,
description: undefined,
keywords: undefined,
modified: undefined,
producer: undefined,
subject: undefined,
title: undefined

Is this a bug? Or is there another way I should be doing this?