CM1000 and SB6183 Dropping Internet

I am about at the end of my rope with my internet with Comcast. Last spring, a contractor cut the line to my house while installing my neighbor's fence and my internet has been dropping out since; sometimes it will take a couple weeks, lately, it has been a couple days or multiple times in a day.

 

I contacted Comcast through chat last Thursday, they blamed my modem (CM1000) and said I need to reach out to Netgear. I told them that I just replaced the modem back in February when I upgraded to 1 gig service but didn't matter. I put my old modem back on (SB6183), downgraded my speed with Comcast to just show the modem isn't likely since both modems I have owned have had the issue.

 

Today (Sunday--three days later) my internet dropped with the SB6183. I contacted Comcast through chat again when the network came back up and they said all looks fine on their end and said the modem is the issue. I told them I have 2 modems and both are faulty?? They then said it could be the router as well and I mentioned I have had 3 different routers in the last year and all lose connection to the internet. I even connected the modem directly to the coax ran from outside the house (removed the wall port) and no difference. My LAN always stays up and I can even go into the modem pages while the internet doesn't work.

 

I don't know what else I have to do to prove that the issue is outside my house and to get Comcast to help/fix it since I don't think it's a coincidence that this started happening when a new line had to be run to my home last spring.

 

I hate the thought of going with the local telephone company because it costs so much more money and I don't even have phone lines in my home but I need stable internet since I am working from home and the kid is doing school online.

 

Can anybody else think of a way I can get this fixed? My upstream channels run all over the place; last week all 4 were below 50 but today they are 51, 51, 49, 48. During the time of the internet dropping, one was at 54, another at 53, and the others at 50. Here are the errors I have seen on both modems when the internet drops:

 

Honoring MDD; IP provisioning mode = IPv6

Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out

Started Unicast Maintenance Ranging - No Response received - T3 time-out

Unicast Ranging Received Abort Response - Re-initializing MAC