The multiple features (points and polygons) are all a toxic chemical from different sources. The grid was created using the 'Grid Index features', so it is a polygon. Some grid cells have no features, some have one, and some have several features from different layers.
I tried Batch Spatial Join and Batch Summarize Within. For some reason, both of these are only counting the last layer listed in the batch in their respective created columns "Join Count" and "Count of Points". How do I fix this issue? Or is there a better way?