Why does Battlefield 6 jitter on Onda H610M?

Parkour landings in Battlefield 6 caused visible screen jitter, with FPS dropping from 60 to 45. I tried lowering graphics, which helped but ruined the visuals. I then used GamePP Power Plan Switcher to set High Performance and lock CPU core voltage. GamePP Frame Time Analyzer confirmed frame time converged to 14-16ms, and Core Temp showed stable 72℃, effectively setting a smooth gameplay baseline.