Why is it when I search for a channel by ID https://www.googleapis.com/youtube/v3/channels?part=contentDetails&id=UU-tdS40X5ld-a4KfarLJuDw&key=[YOUR_API_KEY] I get no items returned.
But when I search by userName, it returns the channel ID that I just searched for https://www.googleapis.com/youtube/v3/channels?part=contentDetails&forUsername=washingtonstateuniv&key=[YOUR_API_KEY]