Shame you couldnt diagnose the issues!I've ended up going back to my 265k build over my 9800X3D because of exactly this.
I love both - the 9800X3D gives me boatloads more FPS (some titles it's 50+ at 1440p) - but everything about the 265k just feels smoother and actually using my PC felt snappier, more responsive and just more enjoyable to use.