empy first array value for cloneable group when using rwmb_frontend_validate

Hi, when using the filter rwmb_frontend_validate with a field which is cloneable group and noticed when i iterate over the array of values that the first array value is empty? why is this as the front end form only displays one set of fields for this group. I want to iterate over the keys and values but wondered why i have to skip the first value? is this deliberate?

field

[
	'type' => 'group',
	'id'   => 'paypal',
	'name' => 'PayPal Accounts',
	'group_title' => 'PayPal',
	'clone' => true,
	'collapsible' => false,
	'default_state' => 'expanded',
	'save_state' => false,
	'clone_empty_start' => true,
	'add_button' => '+ Add PayPal',
	'fields' => [
		[
			'type'  => 'text',
			'name'  => 'Email',
			'id'    => 'email',
			'required' => false,
			'columns' => 6, 
		],
	],
]

output in 'rwmb_frontend_validate' using error_log(print_r($_POST, true));

[19-Jan-2025 15:10:14 UTC] Array
(
    [mbfs_key] => 0b93a40cc6b6156f09107c3b29bd23e9
    [action] => mbfs_submit
    [nonce_dcp-payment-gateways] => 56fce2e58a
    [_wp_http_referer] => /dcplatform/payment-gateways/
    [user_id] => 1
    [data] => Array
        (
            [stripe] => Array
                (
                    [live_secret_key] => ssssssssssssssss
                )

            [paypal] => Array
                (
                    [0] => Array
                        (
                            [email] => 
                        )

                    [1] => Array
                        (
                            [email] => [email protected]
                        )

                )

        )

    [rwmb_cleanup] => Array
        (
            [0] => [\"data.paypal\"]
        )

    [_ajax_nonce] => b7f61d3ba3
)