hi @AdamEm01 ,
There was a similar problem for Landscapes which needed a patch, which is basically about light and Pathtracing is about that
GPU Lightmass not working on Landscape
Have you enable Hardware Ray tracing
have you enabled Direct x 12 and SM6 Shader Model 6 in your project
see also Enabling Path Tracer in Unreal Engine 5.3 | Unreal Engine 5.3 Documentation