ThankQ anon for getting that message out. That was one of my contributions from analyzing the URL's on YT. And in that manner, here is another one. Many videos that you select and try to post here, will not be recognized because they are in a chain of playlists, and you can see that pattern in this URL, for example:
https://www.youtube.com/watch?v=Ddi2TBnzdPo&list=RDDdi2TBnzdPo&start_radio=1
If you trim everything from "&list" to the right, you will be left with the video link that 8ch and 8kun will accept.
https://www.youtube.com/watch?v=Ddi2TBnzdPo