Help Please! Lighting issue

Does anyone know how I can reduce the noise in this level, it seemed to bake fine up until some random point and then started with all this noise in the scene. Any help will be appreciated, currently there is just a sky light, directional light, pp volume and lightmass importance volume in the scene. Increasing to "production quality doesnt fix the issue and my uvs for my lightmaps should be fine, as I said, it worked fine up until a point.