Jitter/Latency issues while playing games

Exact same issue as this person here - https://forums.xfinity.com/conversations/your-home-network/high-jitter-latency-issues-while-playing-gps-games-online/6a4871dddae4694352d4de78

All day for the last couple weeks I will get stutters/jitters while I game (CS2) for example. Happens every 5-10 seconds. Have had xfinity for years with no issues. Had a technician come out and they gave us a new coax cord and a new splitter, and I think that's when the issue started potentially.

Had another technician come out, they replaced the modem/router, issue still is there.

This happens on multiple devices, not just mine.

I've tried changing network settings on my PC and my familys, we all still have the issue. 
Will need to switch providers if this persists.

Below are images from CS2 when I get the jitters, alongside some powershell tests I was running.


I'm not sure what the issue is, faulty coord, etc. but I've had 2 technicians out for this over the last 3 weeks with no fix. Support says that their tests indicate everything is fine. It is not.