New variable shows up when I try to aggregate using the harp squash function

I’m working through a RUS Copernicus tutorial and I’ve been able to aggregate Level 3 TROPOMI NO2 products by day using the squash() function.

However, when I open it up to view the variables in R (which is where I’m doing my analysis), I don’t see the tropospheric_NO2_column_number_density variable that I asked for. Instead, I see a variable called “tropospheric_NO2_column_number_density_count.”

Does anyone know where this variable is coming from and where I can get the one I asked for?

Here is the harp function:
harp_op = "tropospheric_NO2_column_number_density_validity>75; derive(tropospheric_NO2_column_number_density [Pmolec/cm2]); bin_spatial(1600, 41, 0.01, 2000, -95, 0.01); derive(latitude {latitude});derive(longitude {longitude}); keep(tropospheric_NO2_column_number_density,latitude,longitude)"

Here is the squash function:
converted_file = harp.import_product(file_subset, # operations = harp_op, post_operations="bin(); squash(time, (tropospheric_NO2_column_number_density,latitude,longitude))") export_file = "./export/converted_" + i + ".nc" harp.export_product(converted_file, export_file, file_format = "netcdf")

There are the variable options I see in R:
Warning messages:
1: In .varName(nc, varname, warn = warn) : varname used is: latitude_bounds If that is not correct, you can set it to one of: latitude_bounds, longitude_bounds, latitude_bounds_weight, longitude_bounds_weight, tropospheric_NO2_column_number_density_count

Your help would be much appreciated.

Thanks!