A status of NEW_START_REQUIRED could be a result of a few different scenarios.
Synch Not Complete
If the Node40 Monitor is displaying a status of ENABLED, but your wallet is displaying a status of NEW_START_REQUIRED, it may be the case that your wallet has not fully synched the masternode list. We saw this frequently during testing. Masternodes that we could confirm were ENABLED on the network displayed a status of NEW_START_REQUIRED in the wallet. This status would always self correct by keeping the wallet open for a few hours.
The clue to whether you are seeing a status bug or not is to look at the Last Seen column in on the Masternodes tab of your wallet. If the Last Seen is significantly different from the Seen column on the Node40 Monitor page, then your wallet is incorrectly reporting your masternode status and everything should be fine.
Remote Start from Wallet Required
If you have upgraded from a previous version of Dash, but have not issued a remote-start from your Dash 12.1 Wallet within 70 minutes, your masternode will transition to NEW_START_REQUIRED.