Direct Publisher - JSON feed looks good. Nothing is appearing in the channel on the Roku device.

I'm going through the JSON feed on my site, and everything looks good.

In direct publisher, it doesn't show any errors, but the number of videos it ingested is less than the number of videos in the feed.

When I put my channel ID in to a Roku device, the channel comes up, all the channel graphics are there - and there is no content in the channel.

What strategies exist for debugging this? Where can I find a log file to pick apart, or how does this system work exactly?