Callbacks stop working when I add another callback

Dash Python
4

As advised, I tested my function in Jupyter and it was broken (mainly casting in dataframe to float) and now it is fixed but it still ends up breaking my other callbacks when I add it back into.

@app.callback(
        Output("nutrients-table", "children"),
        [Input("add-ingredient", "n_clicks")],
        [State("numerical-amount", "value"),
        State('units-dropdown', 'value')],

    )
    def update_nutrients_table(num_clicks, amount, units):
        '''
        get multiplier from conversions table for correct units,
        multiply by each nutrient by correct amount
        conv_cols of Conversions: Name, Multiplier
        '''
        curr_nutrients_df = nutrients_df.copy().astype(str)

        # todo: if n_clicks reset to zero check for <0 for remove ingredient
        if num_clicks > 0:
            measure_name = ''
            measure_num = -1
            curr_multiplier = ''
            for index, row in conversions_df.iterrows():
                if units in str(row['Name']):
                    # get number
                    measure_name = str(row['Name'])
                    measure_num = float(re.findall("\d+", measure_name)[0])
                    curr_multiplier = float(row['Multiplier'])
                    break

            # divide amount/measure_num
            multiplier_factor = (float(amount)) / measure_num
            new_multiplier = multiplier_factor * curr_multiplier

            # multiply all nutrients by new_multiplier
            for index, row in curr_nutrients_df.iterrows():
                new_row_val = float(row['Value']) * new_multiplier
                row['Value'] = str(new_row_val)

            # return updated_nutrients_table
            # print(curr_nutrients_df.head)
            return make_nutrients_table(curr_nutrients_df)
        #not updated
        return make_nutrients_table(curr_nutrients_df)