This one works indeed.
Here for example (post from 2018), I can not see first vid, and in next post I can not see both vids
3D Game Kit Official Thread page-2#post-3526493
Some other I found quickly
Progressive GPU Lightmapper preview page-2#post-3853231
2D Animation is out of preview for 2019.3 page-2#post-5699227
Trying to Make a Movie using Unity
I am thinking, if it is something to do with youtube playlist, which may be modified …