Heck was leadinding around this time during the election, I wouldn't trust this poll, until final weakend
Heck lost it because he didn't stuck with Trump. Rubio in Florida for example stuck to his Endorsement and never wavered.
BTW,
FOX NEWS will apparently also have a NV Poll out this evening showing Heller ahead. The only Poll where Rosen is leading is the PPP garbarge Poll.
PPP has a strong record. It's best to believe them over a poll that didn't even poll in Spanish or a mystery poll that hasn't even been released (or only exists in someone's head).