Zend certified PHP/Magento developer

Issue with ERP API PUT Request: Unintended Update of `warranty_type`

On Magento 2.4.6:

When our ERP executes an API request on the PUT method /all/V1/product/:sku with the following JSON content:

{
  "product": {
    "custom_attributes": [
      {
        "attribute_code": "delais",
        "value": "30"
      }
    ]
  }
}

Another attribute, warranty_type, also gets updated (its value becomes null) on this product, leading to the loss of information stored in this attribute, even though I did not request this update.

Furthermore, if I attempt to set warranty_type in the custom_attributes during the request submission, it does not seem to update and remains null instead of changing to standard.

Attribute configuration :

        $eavSetup->addAttribute(
            Product::ENTITY,
            ProductAttributeInterface::WARRANTY_TYPE,
            [
                'type' => 'varchar',
                'label' => 'Warranty type',
                'input' => 'select',
                'source' => WarrantyType::class,
                'required' => false,
                'sort_order' => 30,
                'global' => ScopedAttributeInterface::SCOPE_STORE,
                'group' => 'General',
                'visible' => true,
                'user_defined' => true,
                'default' => '',
                'searchable' => false,
                'filterable' => false,
                'comparable' => false,
                'visible_on_front' => false,
                'used_in_product_listing' => true,
                'unique' => false,
                'apply_to' => '',
                'backend' => ArrayBackend::class,
                'is_used_in_grid' => false,
                'is_visible_in_grid' => false,
                'is_filterable_in_grid' => false,
            ]
        );

Note : on Mage 2.4.5, this work correctly

Thanks