function fix_lookup_field( $user_meta, $user_id ) {

    foreach( $user_meta as $key => $value ) {

        if( is_object( $value ) && isset( $value->name ) ) {
            $user_meta[$key] = $value->name;
        }

    }

    return $user_meta;

}

add_filter( 'wpf_pulled_user_meta', 'fix_lookup_field', 10, 2 );