CakePHP 4.5 Custom Validation Rules including Allow Empty

Question

I try to validate a simple form with three fields: modus, range_from and range_to. The validation of the fields range_from and range_to are dependent on the value of field modus. The fields range_from and range_to can be empty if field modus = 1. Otherwise they must have a value and range_from has to be a lower number than range_to. My rules work fine, but as soon as I allow the fields to be empty, all other validations are skipped (also when the field is not empty).

UnitsTable.php

   public function validationDefault(Validator $validator): Validator {
         $validator
                ->scalar('modus')
                ->notEmptyString('modus', 'Please select a billing modus');

        $validator
              ->add('range_from', [
                    'e0' => [
                        'rule' => function ($value, $context) {
                            return (empty($value) && in_array($context['data']['modus'], [2, 5, 8])) ? false : true;
                        },
                        'message' => 'You have selected the modus "weight range", please enter a minimum weight'
                    ],

                   'e1' => [
                        'rule' => function ($value, $context) {
                            return (!empty($value) && in_array($context['data']['modus'], [2, 5, 8]) && $value > 9999.999) ? false : true;
                        },
                        'message' => 'Please enter a weight lower than 9999,999'
                    ],
                    'e2' => [
                        'rule' => function ($value, $context) {
                            return (!empty($value) && in_array($context['data']['modus'], [2, 5, 8]) && !empty($context['data']['range_to']) && $value >= $context['data']['range_to']) ? false : true;
                        },
                        'message' => 'Please enter a weight lower than "Range To"',
                    ]
                ])
                ->allowEmptyString('range_from');

        $validator
                ->add('range_to', [
                    'e0' => [
                        'rule' => function ($value, $context) {
                            return (empty($value) && in_array($context['data']['modus'], [2, 5, 8])) ? false : true;
                        },
                        'message' => 'You have selected the modus "weight range", please enter a maximum weight'
                    ],
                   
                    'e1' => [
                        'rule' => function ($value, $context) {
                            return (!empty($value) && in_array($context['data']['modus'], [2, 5, 8]) && $value > 9999.999) ? false : true;
                        },
                        'message' => 'Please enter a weight lower than 9999,999'
                    ],
                    'e2' => [
                        'rule' => function ($value, $context) {
                            return (!empty($value) && in_array($context['data']['modus'], [2, 5, 8]) && !empty($context['data']['range_from']) && $value <= $context['data']['range_from']) ? false : true;
                        },
                        'message' => 'Please enter a weight greater than "Range From"',
                    ]
        ])
        ->allowEmptyString('range_to');

Unfortunately no validation is executed as long as the "allowEmptyString" rule is there. But when I remove it and the field modus has a value that doesn't need ranges I get the error for the ranges-fields: "This field cannot be left empty". In former cake-versions I was able to add an allowEmpty to every custom rule, is that not possible anymore?

  public $validate = [  
        'modus' => [
            'notempty' => [
                'rule' => ['notBlank'],
                'message' => 'Please select a Modus'
            ]
        ],
        'range_from' => [
            'checkMin' => [
                'rule' => ['checkMin'],
                'message' => 'You have selected the Modus "Weight Range", please enter a minimum Weight'
            ],         
            'maxWeight' => [
                'rule' => ['maxWeight', 9999.999],
                'message' => 'Please enter a Weight lower than 9999,999',
                'allowEmpty' => true
            ],
            'ltRangeTo' => [
                'rule' => ['ltRangeTo'],
                'message' => 'Please enter a Weight lower than "Weight Range To"',
                'allowEmpty' => true
            ]
        ],