Variance in Stock when posting ‘0’

I’m trying my best to explain the issue we’re facing because this seem weird at first.

Here, the total stock is 3, between different locations. We’re able to push quantity date when default quantity is 0 & when we push quantity 1 , then it works

Every hour we run a batch to update stock levels. But, when we want to update quantity from 1 to 0, it does not work.

Here is a summary of batch to processed from ERP to Website

Here is a screenshot of product edit screen