Why does Metaphor: ReFantazio stutter during combat with Corsair Vengeance LPX DDR4 3600MHz?

Frame times jumped from 8ms to 45ms in combat. Disabling the camera broke my stream. I used GamePP Driver Conflict Detector to set Razer Synapse to manual. RivaTuner showed intervals stabilizing at 7-12ms. CPU usage held at 65-72% via Task Manager. Fan speeds stayed at 2200-2500 RPM. The combat flow is finally consistent.