title: Embedded YouTube videos may not play
body: <p>I have created a website that plays YouTube videos using the IFrame Player API.
  Most videos played fine, but some videos didn't load properly.</p>
  <p>One of the videos that causes problems is:
  <a href="https://www.youtube.com/watch?v=mBqt_QO01bA" rel="nofollow noreferrer">https://www.youtube.com/watch?v=mBqt_QO01bA</a></p>
  <p>Website with embedded video
  <a href="https://uta.inui-dondon-sukininaru.net/?sid=233" rel="nofollow noreferrer">https://uta.inui-dondon-sukininaru.net/?sid=233</a></p>
  <p>Some sites have been successfully embedded.
  <a href="https://cn.noxinfluencer.com/youtube/video-analytics/mBqt_QO01bA" rel="nofollow noreferrer">https://cn.noxinfluencer.com/youtube/video-analytics/mBqt_QO01bA</a></p>
  <p>Therefore, you can be sure that the channel allows embedded playback of the video.
  What could be the cause of embedded playback failure?</p>