I am having the same problem, i am losing internet connectivity to my modem AND my X1 box. It used to be once or twice day, but within the last two weeks it's happening 4-5 times a day. Today has been the worst. I have lost internet and X1 box connectivity at least 7 times within the last 5-6 hours making working from home via RDP very difficult. The service map never shows outages but when i look at my service on my phone it shows problems with both connections.
Thank you for the recommendation, having gone through most of that before hand, it's working perfectly, until it doesn't... then it comes back and everything looks fine again... until it's not. Also, it's not just my modem, my X1 box loses all internet connectivity and it's not using my modem.