My router has been rebooting

[MerryHolidays]

6. To rule out electrical issues

Check the breaker box....we had an issue in our new house where the Xfinity cable tv box kept going on and off....I called Xfinity, but they couldn't figure it out. I then called an electrician, and it turned out that a circuit breaker in the panel needed to be replaced.

If that's not it, it is absolutely not normal for a modem to do this.

Can I suggest you call Xfinity and see if they will help. They probably won't since it's your own equipment. However, ask them what speeds you can upgrade to and what kind of equipment you need. I was PLEASANTLY surprised at the massive increases of speed we got (which also helps with multiple users all sharing the same bandwidth) plus HBOMax for pretty much the same price I was paying for speeds 67% below what they were offering. I don't know if you need it (we did), and I had to buy a DOCSIS 3.1 modem for around $159 to take advantage. It was WELL WORTH, since we have several video conferences for work and school going on at our home.