2Gbps plan getting ~420Mbps — OFDM channels showing millions of corrected errors

Hey, hoping someone with access to plant-level diagnostics can take a look at this since I've already gone through pretty much everything on my end.

I'm on a 2Gbps plan but only getting around 420Mbps in real world speed tests. Modem is a Motorola B12 DOCSIS 3.1.

Here's what I've already tried, none of which changed anything: removed and reinstalled the MoCA POE filter (put in a brand new one), replaced the entire coax run from the entry point to the modem with a new 25ft cable, tested with and without barrel connectors, and confirmed there aren't any splitters anywhere in the line.

Current signal readings: upstream power is sitting at 47-47.8 dBmV across all 4 channels, which seems high. All 32 of my downstream QAM256 channels are perfectly clean, zero corrected or uncorrected errors on any of them. But my two OFDM PLC channels are a different story - channel 33 (150MHz) is showing about 18.8 million corrected errors in only 7.5 minutes of uptime, and channel 34 (900MHz) is showing about 17.3 million in the same window. Uncorrected errors are staying at 0 though. I know some corrected errors are normal, but my speeds don't match normal operation. I have also checked at different times throughout the day and I never get about the 500Mbps speeds. I have done every possible thing on my end to ensure it is not on my side. I want my full speed(not exactly guaranteed as I am aware they are not promised speeds), but only getting 1/4 of the speeds I am paying for and have been for a while now is kind of rediculous. A tech came out a while ago and took off something from the line at the drop on the wires. I think an attenuator. This fixed my previous issue for a while which was bad upload speeds and high ping on both sides. Now it is getting any sort of speed that I am paying for. Please fix this.