Likely, you don't have enough public watch hours to be reviewed. Creator Studio shows public & private combined, but you need 4k public hours alone. Try switching private videos to public, or if you've deleted videos you may be ineligible: https://yt.be/help/YPP-review
If the team didn't reach a clear decision during the 1st review, your application is being held while we put extra effort & resources into the final decision. There’s no way to expedite this, we recommend reviewing our YPP Policies given on the previous tweet.