I have Xfinity cable internet. I have always used a separate router and modem and not used Xfinity’s gear. Before Wyze came out with the Pro router, I was using an ASUS RT-AX88U AX6000 Router. It worked ok, but had trouble reaching some areas of my home. I’m now using the Wyze Mesh Router Pro which is working flawlessly.
I am on an 800/20 Mbps plan with Xfinity and using a Motorola MB7621 Cable Modem which is also working flawlessly.
Here is Xfinity’s page on using third party modems: Using Approved Third-Party Equipment for Xfinity Internet and Xfinity Voice - Xfinity Support
This links to another page which gives specific recommendations for third party modems based on the speed of your Xfinity plan: Device Info - Xfinity
I recommend never renting the equipment from Xfinity. The modem I’m using is currently $80 on Amazon: https://www.amazon.com/MOTOROLA-Approved-Comcast-Spectrum-Downloads/dp/B08921BW99?keywords=Motorola+MB7621&qid=1693657559&sr=8-2. The payback is under a year when compared to Xfinity’s rental fees. In ten years, I’ve had to upgrade my modem once when I increased my internet plan’s speed.
With your permission, I’d like to move this DM to the Watercooler public category so others might benefit from the discussion.