Network Congestion - Western WA

I am currently having troubles with my home internet during peak hours. The lag spikes and their resolution are in a particular shape that I believe they may be caused by network congestion. We recently had a tech confirm that our coax splitters are removed, seals are waterproof, and Up and Down SNR and power are within expected norms so I can't fathom what else the issue could be. When charting with PingPlotter I can see local network destinations are resolved without issue.

Has anyone else in Western WA (Southeast Of Seattle) noticed this issue between 5-8pm? Any resolution from Comcast?