Zend certified PHP/Magento developer

Custom Customer Address field not passing validation

I’ve added a custom field to the Customer Addresses with the following UpgradeData:

public function upgrade(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
{
    /** @var CustomerSetup $customerSetup */
    $customerSetup = $this->customerSetupFactory->create(['setup' => $setup]);

    $params = [
        'label' => 'House Number',
        'type' => 'varchar',
        'input' => 'text',
        'required' => true,
        'visible' => true,
        'user_defined' => true,
        'position' =>999,
        'system' => 0,
    ];

    $customerSetup->addAttribute('customer_address', 'house_number', $params);
    $customAttribute = $customerSetup->getEavConfig()->getAttribute('customer_address', 'house_number');
    $customAttribute->setData(
        'used_in_forms',
        ['adminhtml_checkout', 'adminhtml_customer', 'adminhtml_customer_address', 'customer_address_edit', 'customer_register_address'],
    );
    $customAttribute->save();
}

The field properly displays when logging into the Adminhtml area and adding a new Addresses to a customer. However, the New Address form cannot be submitted, the following error appears:

“House Number” is a required value.

Here is a screenshot:

"House Number" is a required value.

I do believe that it is clear that a value for House Number was submitted.

What else must I do to enable this field on this form, and on other forms such as the Checkout and user’s own Account Information?