Dynamic Checkbox Population not working with User Registration - entry data is not being saved into user meta - User Registration Add-On

gistfile1.txt

<?php
// Save user registration entry data to ACF field when activating user based on their original submission
add_action( 'gform_activate_user', 'after_user_activate', 10, 3 );
function after_user_activate( $user_id, $user_data, $signup_meta ) {
    $taxonomies = array(
        'sport_type',
        'age_range',
        'school_year',
    );

    $tax_terms_acf_field_key_on_user = '';

    foreach($taxonomies as $taxonomy_name) {
        $tax_terms_string = get_user_meta($user_id, $taxonomy_name . '_terms', true);
        $tax_terms_slug_array = explode(', ', $tax_terms_string);
        $tax_terms_array = array();

        foreach($tax_terms_array as $tax_term_slug) {
            $tax_term_object = get_term_by('slug', $tax_term_slug, $taxonomy_name);
            $term_id = $tax_term_object->term_id;
            $tax_terms_array[] = $term_id;
        }

        update_field( $taxonomy_name . '_terms', $tax_terms_array, 'user_' . $user_id );
    }
}

// Helper function inside pk_populate_checkbox_tax_term_choices
function pk_check_and_populate_checkboxes($tax_terms, $field) {
    $choices = [];
    $inputs = [];
    $input_id = 1;
    foreach( $tax_terms as $tax_term ) {
        
        //skipping index that are multiples of 10 (multiples of 10 create problems as the input IDs)
        if ( $input_id % 10 === 0 ) {
            $input_id++;
        }
        
        $choices[] = [ 'text' => $tax_term->name, 'value' => $tax_term->slug ];
        $inputs[] = array( 'label' => $tax_term->name, 'id' => "{$field->id}.{$input_id}" );
        
        $input_id++;
    }
    
    return array('choices' => $choices, 'inputs' => $inputs);
}

add_filter( 'gform_form_post_get_meta_2', 'pk_populate_checkbox_tax_term_choices' );
function pk_populate_checkbox_tax_term_choices( $form ) {
    $sport_type_args = [
        'taxonomy'  => 'sport_type',
        'order' => 'ASC',
        'hide_empty' => false,
    ];
    $sport_types = get_terms( $sport_type_args );

    $age_range_args = [
        'taxonomy'  => 'age_range',
        'order' => 'ASC',
        'hide_empty' => false,
    ];
    $age_ranges = get_terms( $age_range_args );

    $school_year_args = [
        'taxonomy'  => 'school_year',
        'order' => 'ASC',
        'hide_empty' => false,
    ];
    $school_years = get_terms( $school_year_args );
    
    foreach( $form['fields'] as &$field )  {
           
        // Initialize variables
        $choices_and_inputs = array();

        switch ($field->cssClass) {
            case 'sport_type':
                $choices_and_inputs = pk_check_and_populate_checkboxes($sport_types, $field);
                break;
            case 'age_range':
                $choices_and_inputs = pk_check_and_populate_checkboxes($age_ranges, $field);
                break;
            case 'school_year':
                $choices_and_inputs = pk_check_and_populate_checkboxes($school_years, $field);
                break;
        }

        if( $field->cssClass === 'sport_type' || $field->cssClass === 'age_range' || $field->cssClass === 'school_year' ) {
            $field->choices = $choices_and_inputs['choices'];
            $field->inputs = $choices_and_inputs['inputs'];
        }
    }
    
    return $form;
}