YouTube API 3 channels by username and id inconsistant
<p>Why is it when I search for a channel by ID  <a href="https://www.googleapis.com/youtube/v3/channels?part=contentDetails&amp;id=UU-tdS40X5ld-a4KfarLJuDw&amp;key=[YOUR_API_KEY]" rel="nofollow">https://www.googleapis.com/youtube/v3/channels?part=contentDetails&amp;id=UU-tdS40X5ld-a4KfarLJuDw&amp;key=[YOUR_API_KEY]</a>   I get no items returned.</p>

<p>But when I search by userName, it returns the channel ID that I just searched for <a href="https://www.googleapis.com/youtube/v3/channels?part=contentDetails&amp;forUsername=washingtonstateuniv&amp;key=[YOUR_API_KEY]" rel="nofollow">https://www.googleapis.com/youtube/v3/channels?part=contentDetails&amp;forUsername=washingtonstateuniv&amp;key=[YOUR_API_KEY]</a></p>