The "releaseDate" field in your feed file is not formatted according to the Json spec. I don't know if that's enough to force the error you see, but, it's something you should look into.
Additionally, be cognizant of the potential 6+ hours that it takes for Roku to ingest channel feed updates.
IT is something on Roku's side of things , i saw quite a lot of posts on this topic.
Maybe someone from Roku could jump in and clarify this.
I have the same issue with some Direct Publisher channels.
What i do to see if everything is ok, i ask friends around the globe to verify for me , because strangely , what i cannot see some of my friends can ( using the same device in some cases , so it is not channel related nor device related) , so the feed is ok , the videos are ok , in conclusion it is on Roku's part.
forgot , @frameworkTV , I installed you channel and i got the same looking glass , asked a friend from the UK to do the same and he can see content - he has the same Roku Express + device like i have , then i asked another friend from the us withe the same type of device , he also can see content.
so back to the same conclusion , not device , not location , not content related.
Let's just hope that someone from Roku will notice the post and provide a proper answer and a way to fix this.
Don't hold out too much hope for Roku support to respond. They provide minimal support here, if at all. You can try to reach out to them by creating an account @ Roku Partner Success. You'll have better success getting a response there.
It could have been related to Roku's blackout period: https://blog.roku.com/developer/2019-channel-store-blackout-dates
Try submitting the feed url again. And yeah, Roku staff does not look at these forum posts in the Dev or DP sections. They used to, until about 2017 or so. I did ask Partner Success to post any future blackout periods as a sticky in here going forward, to which they were receptive to the idea & will consider it.
It is a Roku problem. There is a bug on their end, according to Partner Success. I have several channels that are disabled now, awaiting a fix. This happens often, by the way.