Here's something obscure to try: Your feed defines the video object as a short form video. By definition, a short form video is typically less than 20 minutes. Your feed specifies a duration of 60 minutes. Try changing the type to Movie.
I'd be surprised if that actually works, but, I don't trust Roku to report on feed errors correctly.
Additionally, you may be the victim of some Roku firmware error.
FREE Windows desktop software for converting Direct Publisher channels to SceneGraph (SDK), for creating BIF (Trick Play) files, Roku (MRSS, JSON) feed files, and FireTV feed files @ GitHub/rrirower.