Availability update

Good afternoon, there is such a situation that for some reason the box sends goods with the correct quantity, then either without the availability status and comical situations come out when there are 3 goods, but it writes in the product card that it is not in stock and vice versa, the goods are 0. in stock, you can not put it in the basket, but all the buttons for ordering are active. Where and how to see the logs that Rest API writes to the database? How to understand what the problem is and how to fix it? Or just look at the code. We have been looking for this problem for a week now and all in vain. Starting a new project in such a situation is not possible.