Please see attached jsfiddle for a representation of what I am trying to do:
As you can (hopefully) see, this renders correctly in most browsers, but in Firefox the iframe will stay empty. In addition, the data that is returned from the createTimeline promise is undefined.
Is it possible to use the API this way to load a timeline? If so, what am I missing here?
All browsers I am testing in are up to date, but for more specifics: