The stock item was unable to be saved. Please try again

I’m running a custom import.

At some point the error: The stock item was unable to be saved. Please try again.

Is triggered by : $this->_productRepository->save($prod);

Now I’m trying to figure out why.

MariaDB [magento]> select * from cataloginventory_stock;
+----------+------------+------------+
| stock_id | website_id | stock_name |
+----------+------------+------------+
|        1 |          0 | Default    |
+----------+------------+------------+

Is the fact I only have one stock there might be related? This script is launched by an URL from one of the front stores

MariaDB [magento]> select * from inventory_stock;
+----------+---------------+
| stock_id | name          |
+----------+---------------+
|        1 | Default Stock |
|        2 | Stock RE      |
|        3 | Stock YT      |
|        4 | Stock GF      |
|        5 | Stock MQ      |
|        6 | Stock BL      |
|        7 | Stock GP      |
|        8 | Stock SX      |
+----------+---------------+

I indeed have 8 websites (0 being an admin and 1 being base) website and stocks

EDIT : So I’ve been investigating a little bit more

It appears that my real error comes from vendor/magento/module-catalog/Model/CategoryRepository.php on the get method

He can’t find the category

        /** @var Category $category */
        $category = $this->categoryFactory->create();
        if (null !== $storeId) {
            $category->setStoreId($storeId);
        }
        $category->load($categoryId);
        if (!$category->getId()) {
            var_dump($storeId);
            var_dump($categoryId);
            var_dump($category->getCollection()->getSelect()->__toString());
            throw NoSuchEntityException::singleField('id', $categoryId);
        }

Store id : 10
Category Id : 50

Error : No such entity with id = 50

Problem is, the category actually exist; she is even found when I log the collection matching the request

SELECT `main_table`.`entity_id`, `main_table`.`level`, `main_table`.`path`, `main_table`.`position`, `main_table`.`is_active`, `main_table`.`is_anchor` FROM `catalog_category_flat_store_10` AS `main_table`

Among other results I have this one :

+-----------+-------+---------------+----------+-----------+-----------+
| entity_id | level | path          | position | is_active | is_anchor |
+-----------+-------+---------------+----------+-----------+-----------+
|        50 |     2 | 1/2/50        |        2 |         1 |         1 |