There is an issue in (at the time of writing) Magento 2.1.4 and previous versions that doesn't update the field updated_at in the table catalog_product_entity when a product is updated. This simple module uses raw SQL to force update the field.
Use this module at own risk and make sure to test it first!
After installing Magento 2, run the following commands from your Magento 2 root directory:
composer require codepeak/magento2-productfix
php bin/magento cache:flush
Feel free to fork and contribute to this module. Simply create a pull request and we'll review and merge your changes to master branch.
Codepeak is a Magento consultant agency located in Sweden. For more information, please visit codepeak.se.