I just purchased a new Ring Gen 2 doorbell and plugged it in for the first time to charge it. It started flashing blue as it said so I left it charging for about 8 hours. It eventually went solid for a few seconds and then started flashing again and then it would go solid again and keeps repeating like this. I unplugged it and pressed the orange button on the back and nothing happened even after pressing and holding in the button for about 15 seconds! Do I have a dud??