We are currently not getting unclaimed videos from the YouTube report CONTENT_OWNER_ASSET_DEVICE_OS_A2 because we can only fetch claimed videos. From what I'm told the reason we don't claim some videos is because we have other channels that repost the same video, if we claimed those reposted videos it would cause copyright issues in YouTube.
We found this article that might fix this for us so we can then claim videos and we can see the data come through the report, but I'm not entirely sure its what we're looking for, hoping someone can clarify: