While we can't share specifics. You should have received an email and a notification with more info in Creator Studio. Take a look at those resources and note that you can always reapply for the YouTube Partner Program again in 30 days. More info: https://goo.gl/3Y6GYn .
Thanks for confirming. If you're waiting for an update on the second review, we don't have an exact date or time frame. It will happen in the near future. In the meantime, keep uploading original content as the more info/content to review, the better!