It seems to be less reliable than before, hc. Earlier this week I posted a handful - some worked, others not.
There was a suggestion that removing the dot that sometimes turns the 'youtube' part of the URL to 'youtu.be' would work - again, sporadic - and the same was true of ensuring the URL is placed on a separate line.
The odd thing was that sometimes just the URL appeared, sometimes a black box of the same size as the usual preview (and clicking it didn't work).
Links with youtu.be never have embedded the videos here but they've still appeared as a clickable link, rather than as an empty box. Perhaps that's what's changed?
Youtube.com links appear to be embedding as normal.
Mikey - as far as we can tell, if you make sure the URL is on its own line it should work. But if the URL has 'youtu.be' rather than 'youtube' it will probably appear just as a clickable link, unless you put it on a new line, in which case I think you end up with the useless black box.
I think. And I've made it sound ridiculously complicated.