Guys, I created a page to punitor the products that have this problem.
What's the downside: A public page will be created with all the products of your ecommerce, I recommend creating a very complex link and disable the indexing of thefts.
Let's take the steps:
01- Create a page-checkstock.php with the following code: https://github.com/odirlon/checkstock-error
02- Change the line 84 to receive the notifications.
03- Create a page with a complicated slug like this: "check-stock-2452233213321653441" and use the template created in the previous step.
04- Create a cron to check the page from time to time on the site: https://www.easycron.com/user
05- Ready, now whenever a stock bugar you will receive an email notifying you, or if you want to see if the site has an error simply access the page you created.
Remember to remove the cache from this page.