Funny, I'm here for the exact same issue that I've been researching for over a month now and it's odd I stumble across the same reddit post that I commented in.
I had a Cox tech come out last week. He 'reset' everything in my house and when he was done he said he fixed my issue. He handed me a small metal device that he called a packet capture and said it was used to provision data for uplink. I bought it for about a day and a half since it seemed to fix my issue. Before he left I verified my uplink had 4 locked channels instead of 1 and I played a few games of Fortnite throughout the day with almost 0 packet loss. It was glorious! There was 1-2 instances where I saw packet loss go to 2% but only for a second or 2. Next day, internet went out, I cycled the modem and the packet loss was back with a vengeance.
Pretty safe to say the tech gave me some nonsense and went about his day. If there were another ISP alternative in my area I'd have already switched but Cox is just short of a monopoly in my area and apparently that entitles them to sell a 'premium' service built on a sub-par infrastructure.
I'd post my tracert output as well but it's nearly identical to what's already linked above.