Monaco editor intellisense for properties containing abnormal characters not working (typescript)

I'm trying to get the monaco editor's intellisense working for object properties that contain spaces, commas, colons, etc.

Editor options are as follows:

monacoRef.languages.typescript.typescriptDefaults.setCompilerOptions({
    target: monacoRef.languages.typescript.ScriptTarget.ES2020,
    allowNonTsExtensions: true
});

Example code:

myProp = {
    'strange prop name': 2,
    'dd MMM yyyy:HH:mm.ss': 3
}

When these characters are introduced the properties no longer appear after typing a period after a class/variable.

This is working in VS Code while I'm working in my IDE but not in the monaco editor. This suggests that this functionality is supported. Does anyone know how to get this working in an instance of the Monaco editor?

(working is vs code)

(not working here: https://microsoft.github.io/monaco-editor/)