It was DPC latency. So just in case, someone has a similar problem, the culprit was iCUE, a driver for Corsair products. According to LatencyMon, the latency was coming off faulty USB chipsets AND bad audio drivers AND the DirectX Kernal. My DPC went away when unplugged my Corsair keyboard, and after I uninstalled and reinstalled the drivers, it all went away.