Form validations for non-required fields

I'm trying to add some form validations to a site I'm working on. I was able to get the validations to work on the fields that are required but as I'm trying to adjust the code for the non-required fields that still need to be validated when there is user-input I'm running into some issues.

This works pretty flawlessly if the field is required but when I make the field not required, the form doesn't submit and puts out an error message if I leave the field blank.

add_action( 'elementor_pro/forms/validation', function ( $record, $ajax_handler ) {
$fields = $record->get_field( [
    'id' => 'dot',
] );

if ( empty( $fields ) ) {
    return;
}

$field = current( $fields );

if ( 1 !== preg_match( '/[1-9]{1}[0-9]{5,7}/', $field['value'] ) || $field['value'] == '123456' || $field['value'] == '12345678' ) {
    $ajax_handler->add_error( $field['id'], 'Invalid DOT#' );
}
}, 10, 2 );