Connectivity Problems - Frequent T3 Timeouts

Hello! Around the end of May we started experiencing intermittent connectivity problems. We replaced our modem with a brand new one (an Arris SB6190), and that didn't help. The new modem's event log and status page showed frequent T3 timeouts and upstream channels dropping out.

A technician came out in early June and did some work on the connection at the side of the house. He then checked the line between the side of the house and the back of the modem and thought everything there looked fine there. After he left, the issues resumed, with connectivity dropping sometimes several times each hour.

A more experienced technician then came out and ended up replacing a connector on the utility pole that feeds the house. For maybe a day or two everything seemed great! However, the issues have resumed. The modem logs show frequent T3 timeouts, sometimes high numbers of correctable and uncorrectable codewords, and fluctuating upstream channel power values that seem to be sometimes toward the low end and sometimes toward the high end of the acceptable range. There are no splitters in the line.

Is it possible there’s something strange happening with the CMTS or the node? If so, is there a way to escalate this to someone who handles that? Or is my best bet just to start with an agent again and see if they are willing to send a third technician out?

I'll post some event log entries and downstream/upstream values below in case that is useful. Thanks in advance for any insight or assistance.