Tech Scheduled and need advice on how to escalate if needed

TLDR version: Are there "levels" of techs sent to the house? Different levels of experience, etc?  And how should i proceed, document, escalate to higher level of service to have the tap and line to road examined if this upcoming service visit again does not fix my ongoing issue?

we have had very unstable internet for years. neighbors do not have this issue. We had frequent latency spikes, packet loss and dropping of internet. 

In december of 2024 a new line was buried from pole to side of house. A tech redid the line from the tap, down the pole to the buried coax at base of the pole.

I replaced all coax in house. only a single splitter with a line to a cable box and a line to modem. I bought arris sb8200 and then netgear CM3000, which i currently have. 

Two tech visits in april of this year on 4/5 and 4/13. the first tech in april did not check the tap.  Symptoms persisted and scheduled another technician for 4/13. this tech did check the tap and found this at the connection on the coax where it connected to the xfinity tap. this center copper was was too long and gouged, and they presumed likely may have damaged the tap or been the cause of the interference.

The April 13th tech redid new coax line from the tap to the underground line, which runs to the house. It was rg6 and not rg11 as we are nearly 200 feet from the pole.

however, things seemed much better and stable for months.

but symptoms have returned over the last week. intermittently at first and now massive instability over last several days. T3 timeouts, upstream power becomes maxed out. for a few days, rebooting or disconnected coax from house and reconnecting would allow an "ok" connection for a few hours. But then instability develops, upstream power increases and starts to drop.

I have taken my modem and router, to the coax coming inside the house, to remove all my wiring from the equation. Even at the side of the house, connected directly to the buried rg11 line from the pole, the modem upstream is unable to maintain channels and power level 54.8 dBmV.

I took the modem and router, to the coax coming directly from the tap, out at the pole on the property. The modem still, was not able to get full upstream channels and the power needed to communicate was still 54.8 dBmV.

Fairly certain, this is an issue with the tap itself or the line from tap down to the main distribution along the road.

So trying to figure out how to get higher level tech who can better trouble shoot these issues.

https://forums.xfinity.com/conversations/your-home-network/frequent-latency-spikes-and-loss-of-internet-looking-for-next-steps/69cd45b3d22c2e5c79730096?commentId=69e273ad9a42897977759c9e