My .02, I’ve had issues from day one.
My WP Core embeds work great. I take a simple Youtube video, throw it in a post, preview or save, wham…video embeded just fine.
Hit the Embedly button, paste in same url…churns…churns…nothing.
Go back the next day, do the same thing, works fine.
Tested this from 5 different clean installs of WordPress – 1 dedicated server, 2 VPSs, existing shared hosting install and new shared hosting install. Same story each time. When one works, they all work. When one starts churning, they all start churning.
If there is an issue, divulge. Works great when it embeds, but most of the time, it just doesn’t get that far. Is this going to be fixed, or should we look elsewhere?