Extreme Lag, High Latency When Gaming

I have been having an issue with extremely large ping spikes when playing various online games via Ethernet to my PC. I have been experiencing this since about mid Feb. The issue was intermittent and what appeared to be random when it started. Currently it is happening with the highest severity every night around 10:00pm MT. During the afternoon I will see ping spikes of about 100ms-350ms. Around 10pm I can see ping as high as 20,000ms! This is followed by complete disconnection from my game, from discord and the internet will drop completely.

I have thoroughly troubleshooted my network to the best of my ability. I have even changing from owning my own modem(Arris Sufboard S33) to renting an xFi Gateway because the rep on the phone suggested it as a solution. It did not resolve the issue in any way and the plan change did not yield to speed boost to 1300Mbps. Today I had an Xfinity Tech come by the house to take a look. He said he measured interference in the network and saw that there was an expired splitter in the line and an unnecessary one at that. He removed the splitter and ran the coax from outside into the one on the inside, without the splitter. This did yield download speeds of up to 1400Mbps, which I had not seen yet. This was around 1:15pm.

It is now 11:45pm and I am experiencing the high ping again, upwards of 5,000+ms, while gaming and have had my internet drop completely while not in a game at all. Speed reduced to 550Mbps. Some extremely server drops have been as low as 16.9Mbps Down and 2.8Mbps Up. In some cases, on Xfinity Speed Test, "Upload Speed" and "Latency" have resulted in "Error", without any values recorded.

There have been multiple days where there has been maintenance in the area. My hope was that this issue would be resolved, but neither the maintenance in the area, nor the tech coming to my home resulted in a resolution of the issue. This is issue has been going on for over 2 months and all I have to show for it is a contract for signing up for 1300Mbps and a rental modem and probably a $100 charge for the tech to come out. I would really love to see a resolution to this. It is not only gaming that has been degraded, but also video calls for business meetings.

Any help is appreciated.

Here a spreadsheet of my Xfinity Network Metrics @ about 11:50pm.DOWN/UP and CM Errors