Need some help with a DOCSIS 3.1 cable modem

[MerryHolidays]

Hi All:

I need your guidance on my home network. I am on Xfinity internet and just switched to a DOCSIS 3.1 modem (Motorola MB8611) a few weeks ago. My family, which is doing videoconferencing for work/school, is complaining that we are now getting internet drops from time to time, and usually at the worst time. We are using a Google WiFi mesh router (and have been doing so for years, now).

When I got the new modem, I upgraded our Xfinity plan to the 1gps plan. Our speeds are amazing, but the intermittent drop in internet is not acceptable. Both the family and I need a constant reliable connection (as do we all), given that we will be attending work/school online for at least the next few months. Even after the pandemic nightmare subsides, I need a reliable connection for work.

I spoke to Xfinity customer service, and they see no problems on the cable line. I also spent HOURS with Google to see if there were any issues with mesh router. While Google was all over the place and not very focused, I did perceive that the router is not the issue. Based on the complaints from my family about dropped internet that occurred after I installed the Motorola modem late last month, the troubleshooting with Xfinity and Google, and logging into the modem and checking event logs on the modem, the only thing I can think of is that the modem is not working properly. I checked some reviews online, and several have complained about precisely the problem we're having with this modem.

I am thinking about returning the Motorola modem (I still have a few days left in the return period) and getting an ARRIS Surfboard S33 DOCSIS 3.1 modem as a replacement. It's not cheap, but over time, it is cheaper than renting an Xfinity modem. Regardless, I need a solution that works.

First question: are there any software tools that a non-network engineer like me can use to isolate/trace the source of the issues and problems? I would rather not return the Motorola without making sure, as best I can, that it is the source of our problems.

Second question: do any of you have experience with the ARRIS modem? I think I've read here that some have it. I am ok to get a new modem and replace the Motorola, but I don't want to go through the hassle if the ARRIS also has problems.

Any guidance you can give would be great and definitely appreciated!

Thank you in advance.