Why does Kingdom Come II stutter in neon areas with Path Tracing?

Neon lights flickered and tore the screen, breaking immersion. I tried lowering RT to High, but the lighting looked terrible. I used GamePP Shader Compilation Queue Manager to clear the 6.8GB cache and installed Studio Driver 560.94. RTSS showed frame time stabilized to 13-16ms from 22-35ms. HWiNFO reported 58-64°C. GPU-Z confirmed stable VRAM at 12.4-14.1GB. The visuals are crisp now.