Validation callback problem in CakePHP 4

Hello, everyone. I have two fields in a form, one dropdown and one text:

echo $this->Form->control('label_id', ['label' => 'Sensitivity Label', 'empty' => true, 'options' => $labels]);
echo $this->Form->control('distro_notes', ['label' => 'Distribution Notes (Required if a PROPRIETARY or CONFIDENTIAL label is chosen)']);

Field distro_notes is only required if certain label types are chosen from the dropdown. There are six available, and distro_notes isn’t required for the first two. My validation rule looks like this:

        ->notEmptyString('distro_notes', 'This field is required if a PROPRIETARY or CONFIDENTIAL label is chosen', function ($context) {
            $labelIds = [1,2];
            return !in_array($context['data']['label_id'], $labelIds) && empty($context['data']['distro_notes']);

The validation executes on distro_notes regardless of which label is chosen, when it should be allowed to remain empty if label_id == 1 or 2. What am I missing?