Frametime spike exactly every 10 seconds

I have this weird issue where I have a frametime spike in at least 3 games I've tried, CS2, DayZ and Forza Horizon 6. I have confirmed the spike happens at exact 10 second intervals with CapFrameX.

I like to think I'm very tech savvy and I've pretty much tried every single thing under the sun to fix this at least software-wise.

I have reinstalled 3 different Nvidia drivers after DDU. Tried installing just the driver without any bloat with NVslimmer. Disabled all overlays. Unplugged all USB devices. Updated BIOS. Tried all default settins in BIOS. Updated chipset drivers. Disabled LAN and audio drivers. Disabled HPET. Disabled AMD Cool n Quiet. Disabled C-states.

Finally I reinstalled Windows yet the problem still persists. Every 10 seconds there is a big frametime spike. Sometimes it's every 5 seconds. Like in CS2 main menu it's every 10 seconds but when I join a match it's every 5 seconds. It's like something is peristently polling the system causing that spike at regular intervals.

I'm at my wits end. Pls help.