Why YouTube playlist preview works fine in editing, but failed after posting?

[SkyLin]

The situation is:

1. Some urls works fine but some NG.
2. Preview works fine in editing but failed after posting.

Please refer to the attached screenshot.

figure 1. YouTube playlist after posting

figure 2. YouTube playlist in editing

And here I post the url again below:

https://www.youtube.com/watch?v=oR6G1MUMveE&list=PLoROMvodv4rMz-WbFQtNUsUElIh2cPmN9&index=1

https://www.youtube.com/watch?v=ilmw-ifriyw&list=PLxHlVV5gCbcM6Vyqa1vOKwyH2VuJ8l9BM&index=1

[SkyLin]

Looks like it’s the reason, the owner disable playing outside YouTube.

The onebox preview works in editing due to it’s image, not video preview.