Intermittent Channel Dropouts on Modem

Hello!

I'm trying to figure out how to escalate this. 

I recently moved to a new house. I installed my own modem that worked without issue in my last two apartments, but I started having internet dropouts when it was installed at my current house.

I had claude write a python script to monitor my modem channels for errors and SNR, and had that script live on a NAS that is always up. 

I found that there's a bunch of errors on CH17/18/19 (579-591 MHz) , without many/any errors on other channels. When those errors occur on 17-19, the modem started trying to re-initialize for 5-60 minutes. After that period of time, connection is restored and there's no more errors. 

I found out that I have to pay for a technician to come out with my own modem, so I swapped to an Xfinity modem. I'm still having the same dropouts, but I don't know how to actually monitor the channels. It seems like the Xfinity modems are locked down / disallow much local diagnostics. 

What I do have is a script running to ping every minute or so and verify the internet is reachable. I've mapped out a outages at different times of the day, but haven't completely established any pattern for dropouts -- except that they're usually 30-60 minutes. 

I have no other devices on coax (no MoCA, no cable TV). I put in a MoCA choke and a new splitter at the service coax going into the house, and eventually just bypassed all of the house coax and installed the modem right at the service coax. This did not have an effect on the issue.

The service coax is an orange coax cable that is buried in the yard. My suspicion is that there's a splitter between a main coax and a few neighboring houses, but I'm pretty sure that's getting into the Comcast realm of troubleshooting. 

Does anyone have any advice on how to get this information communicated out before a service visit? Would any type of log help, or is there a way for Comcast to log a modem / verify modem-level outages?

Thank you!