How can I stop frame rate fluctuation in Unreal Engine 5 demos on my Manli Snow Fox RTX 5050 OC?

I was testing a UE5 demo project and my frame rate was bouncing wildly between 60 and 75 FPS, which made the visuals look inconsistent. I initially blamed background services and disabled several processes, but the fluctuation persisted, causing real anxiety about my hardware stability. I realized the issue was likely the Windows power plan limiting the GPU's performance headroom. I used the GamePP Power Plan Switcher to confirm the system was in 'High Performance' mode and disabled the Windows Game Bar to reduce overhead. 3DMark validation showed the frame rate stabilized at 80-85 FPS. HWiNFO64 confirmed the core temperature dropped from 82°C to 76°C, and CapFrameX recorded a smooth 11.