I was using my own modem, but decided I needed hot spot, so I end up renting comcast modem. I don't know if the modem that comcast gave me is faulty but the modem that I owned, the internet rarely goes down, maybe once a year....Technically, the internet is not down, all the lights are on, the only way I can get hotspot/internet back is by restarting the modem. It's been like this ever since I rented the modem. I tried factory resetting it and power cycling the it as well.
Here's my signal my upstream
Here's my downstream
The signal stats are o/k. Try getting it swapped out for another. Good luck !