3D chart producing invalid mesh

Hi everyone. I’m currently trying to plot a 3d chart of outdoor comfort and it seems to be working fine. The only problem is that the mesh 3D chart produces seems to be very invalid. I’m hoping to use mesh to hatch so I can bring this information into illustrator but of course can’t because it’s invalid. Does anyone know if there’s a simple way to fix this. I’ve got Z said to 1 and the mesh produced has a lot of non manifold edges which I suppose is to be expected as it’s essentially hundreds of extrusions meshed together. Any help would be really appreciated