Unfortunately, I don't. Most of the ones I used to frequently chat with on this site have gotten busy offline so I know far less now than I did a few years ago.

Even back then it was a struggle. The YA group didn't ever really get off the ground much as there was only a couple people who posted anything before it became inactive. Haven't seen any contests that focus on it survive either though I know a fair number of contests (genre focused and otherwise) definitely allow YA stories. The contests are good for practice and many of us judges try to provide reviews/feedback when we can.