Why does Aka stutter during combat effects on RX 9070 XT?

Every skill release caused a jitter, dropping from 120 to 90 FPS. I lowered graphics, which felt like a loss. I used GamePP Resource Scheduler to set Real-time priority and adjust thread affinity. Process Explorer showed CPU usage stabilized at 75-85%. The frame time analyzer confirmed smoothness, so I set the final profile.