Intermittent lost connection – signal strength, length of run / splitter (booster) issue? What’s the

Experiencing intermittent loss of our internet connectivity

We have

• Run the usual troubleshooting on the equipment multiple times (on / off, check cables, reset remotely via agent)
• Replaced the modem and internal caballing to the modem, once with Xfinity supplied equipment installed and verified by a Comcast tech, this last time with NETGEAR from Best Buy (Nighthawk 32 x 8 DOCSIS 3.1 Voice Cable Modem, Voice support), installed and verified by their Geek Squad tech
• Had 2 onsite visits from Comcast technicians – both inspected the installation, from the tap at the street to the termination of the run at our house in a splitter block / booster (Commscope CSMAPDU9VPI), including verifying that hardware was powered on and operating correctly

See here for a simple diagram of the system configuration

At this point I believe the issue is with the connection from the source lines along our street to the house, through the splitter / booster, to the modem perhaps confounded by variation in the source signal strength. That is, the modem is not receiving a consistently strong enough signal to establish and maintain connection and cannot recover one when it is lost.  

I have a home office, separate standalone structure, on our property that is ~ half the distance to our home from the street. That has a separate internet connection and account, with a similar setup – 3rd party modem (Surfboard) and WiFi router (Linksys). I have had zero issues with connectivity. The home office setup is newer in this regard (buiilt in 2015) and a shorter run (to the extent that makes a difference)

I am not a networking expert… I do however have a long history and deep background in electrical / mechanical / systems engineering and software….  so pretty sure there is a way to diagnose, debug what is happening with the signal from the source connection to the home, directly with some diagnostic device / tool I don’t have (presumably Comcast or it’s vendors, others do) or indirectly through whatever logs the modem is putting out and whatever tools exist to make sense of these…

Much appreciate any help here!