Unstable Internet Blamed on Voltage

I have been working at home since Covid started and have been dealing constantly with packet loss and unstable internet which results in getting kicked off my VPN about every 45 minutes to 1.5 hours in the workday.  I've logged many calls about this, and after the first 4 technicians checking cable connections, the 5th technician came during at time where the signal was very weak at the street box.  He called in line techs and explained that I was at the end of a very long node, then asked if I had checked for voltage.  He verified there was no voltage from the service side, but saw 40ish V on the two branches to the cable box and to my modem (see picture).  He then explained that it isn't the service that is causing the issues but voltage and told me we would need to get an electrician.  I paid ~400$ for an electrician to come out, and they didn't find anything wrong.  Must have had a different multimeter as they didn't detect any voltage.  I then called Comcast back out and a super experienced tech came out and called out line techs as the signal was super low again.  He also checked the V which showed at 40V, which I have been verifying using my autoadjust multimeter during my own troubleshooting.  I overhear the line tech express that there are 13 cascading nodes, which the service tech expressed surprise at how long that was.  I don't understand it, but it sounds like I am at the end of a super long node and getting the scraps leftover.  He also said that the service still wouldn't be the issue and that I need to figure out the Voltage issue before contacting Comcast again.  Since then, I have switched circuits, ran an extension cord to a neighbor, double-checked all the outlets for shorts, scrubbed connections and ensured the panel neutral was connected to the grounding wire outside.  I even had PSE (electric company) come and do a load test to make sure their neutral was good.  I just had a frustrating breakthrough today when I finally isolated the voltage leak... it is the cable box and the modem!  I took voltage directly from the back to ground and found the same 40ish Volts coming from the back of the cable box and the modem.  Given these have been replaced a couple times, and they don't have a grounding plug, I am now frustrated at the runaround I have received over the last 18months.  I'm calling Comcast again, and am hoping anyone on this forum has had a similar issue and got resolution.  I'd love to hear if anyone understand the 13 cascading nodes comment.  I've attached a picture of the layout in case anyone has any questions.