This is not an issue with the module but stems from the following PrestaShop bug:

https://github.com/PrestaShop/PrestaShop/issues/29206

The report concerns strange behavior of the “DisplayAdminProductsExtra” hook when the product description does not contain the <p> tag. In summary, a user found that when clicking the configuration button on some products, PrestaShop does not load the .tpl file as it should. This problem does not occur on all products, but only on those whose description is in pure ASCII text without HTML tags.

The user discovered that products that function correctly have their description enclosed between <p> </p> tags, while those that do not work have descriptions in pure ASCII text, often due to product importation. Manually modifying the description by adding <p> tags resolves the issue for that specific product.

The request is for the product page to ignore HTML tags when transitioning to the module and also accept descriptions in pure ASCII. The user emphasized that their module has nothing to do with the product description; it only serves to display a .tpl file with additional product fields to be loaded into an external table.

The issue has been confirmed and reproduced by other users and reported as a regression (a new bug introduced after an update) in PrestaShop versions 1.7.8.x, but not in version 1.7.7.8. The problem has been marked as significant and requires further specifications to be resolved.