Poor line quality, problem with feeder coax or plant?

Hey guys, my name's Kyle. I've been having a little issue with a new modem install. I currently have the 1.2 gigabits per second plan from Xfinity. For the longest time, I've been running a Netgear CM1000. It was working ok, but I had bad latency and issues with it not syncing.  I noticed on the Xfinity site that this modem wasn't recommended for my plan, so I bought a Motorola MB8611. When I first moved to this house, I had always had difficulty getting my modem to sync up (cm1000). The modem would immediately acquire the downstream signal, but the upstream signal would never lock. It would just sit there and blink during startup. I would restart the modem until it finally locked onto the upstream signal and gave me Internet access. I sometimes had to do this three or four times until it worked. I noticed that the event log for my CM1000 was littered with upstream-ranging response failures. It was a complete hassle. I hoped this problem would be resolved after I got the new modem. Seeing as that's what was recommended.

Well, the new modem was having the same issues. And even possibly to a larger degree. This prompted me to double-check all the connections throughout my ceiling to ensure all my coax cable was good. The MB8611 did not like the VoIP amplifier it was going through (Commscope CSAPDU9VPI). I don’t have VOIP and never will, so I took that out and used a female splice from the plant feeder to the room with the modem.  After I took that out of the coax loop, it would acquire an u/s signal after 2-3 restarts instead of never from the room- giving me internet.  But I still had many errors, and only the u/s channels wouldn’t bond, giving me a flashing u/s light.  All the connections are tight, and none of the coax is being kinked. I then factored out my house coax and tested the MB8611 connecting straight to the feeder cable from the plant in my garage. It did acquire the upstream signal; however, the event log was still littered with critical failures from the upstream side. And three of the channels would not bond-still with a flashing u/s light. I'll attach the event log and connection log in the post following this initial one. I've determined that something is going on either at my incoming cable to the house or a problem with my plant. I need to get a tech out here to verify. Can anybody help me with that?