Why does path tracing cause frame spikes in Farming Simulator 25?

In night neon areas, path tracing caused severe color bleeding and 22-35ms frame spikes. I tried lowering RT to High, but the visual quality drop was unacceptable for my setup. I used GamePP Shader Queue Manager to clean install NVIDIA Studio Driver 560.94 and clear the 6.8GB shader cache. RTSS confirmed frame times stabilized at 13-16ms, and GPU-Z showed VRAM usage holding steady at 12.4-14.1GB.