Frequent outage - SB8200 issue here also!

Xfinity upgraded me to an 800 Mps plan last April 2021, about the same time I started experiencing frequent internet outages. I gave up trying to get it fixed by calling Xfinity's tech support, since they just read a script and prescribe the same resets and reboots every time. I decided to buy a new Arris SB8200 since it runs the latest DOCSIS 3.1, handles gigabit speeds, and is on the Xfinity approved list.

I see that I am not the only one with an SB8200 suffering these madding disconnects.

Since April, I experience outages lasting from 3 minutes to more than 30 minutes, averaging about ten per week. Powering off the modem usually does not fix the problem - the modem cannot connect.

What does work, I figured out, is if I disconnect the main coax drop from the utility pole from the Xfinity-supplied powered splitter and connect it directly to the SB8200 - the cable modem will reconnect after waiting about 4 minutes for the reboot.

The powered splitter has three other TV coax lines to feed three TVs. It was just replaced by Xfinity during one of their several visits to my home. I printed out my router's Status and Event Log, but I really have no idea how to interpret them.

I have had the outside line and neighborhood junctions inspected (supposedly) by an Xfinity tech after the in-house tech ordered the inspection. 

Can anybody help me diagnose my problem? Thank you