Internet Connection issues C6300

My modem has been failing for a couple days now. The first day, I called and they told me the Modem wasnt registered with my account at xfinity comcast (ISP). So I gave them the MAC address and got it added to my account. Internet service was back up and then again out of no where the next day the Internet went out. They set it up again and the internet was back up. And then the next day (yesterday) it went out again. I called and they told me something was wrong with the "Boot file" and the person i was talking to sent me to someone else and told me to tell them that my boot file were already provisioned but it kept coming back. After 45+ min on the phone and many reboots, they told me to contact netgear directly because they couldnt go through the settings of my modem. As of right now, im using my old modem to connect to the internet, and it works perfectly. Reasurring me that the problem isnt the ISP or the cables, its the Modem.

ps. when i connected my Netgear modem to my computer it told me that i did in fact have internet connection but i had to call xfinity to get logged in.