Id be willing to take a look but I can’t guarantee a solution. Open worlds are complex and b ottlenecks can be caused by many things. Try resetting your PostProcess and see if that effects your FPS. Grass is also a common bottleneck as is a lack of proper LOD’s. Lighting can also cause issues. Texture streaming, Opacity, emissive, high polycount, WPO, POM, particles, interactivity,it can all add op. Try learning about the GPU profiler, shader optimisation mode etc.