Thanks for reaching out. Just to confirm, was your channel monetized earlier and now demonetized or is it the first time you've applied and were rejected? Also, please share a screenshot of what you’re seeing on this page: https://goo.gl/297Xrv
While we can't share specifics, here's more about reused content & how you can avoid them in future videos: https://goo.gl/E5dgGo . You can always reapply for YPP again in 30 days. Hope this clarifies.