Frequent / daily occurrences of P4111 detail and summary qty variances

In our system, for over a month now we have observed increased frequency of P4111 detail and summary qty variances.

We have a custom report / application to identify and then update these variances. but sometimes even this report doesn't catch the variance even though variance would exist.

In fact now it is almost always the case that any sales order received / sales order sales updated will surely not reflect in summary qty until we run our custom report to fix this variance.

Do not find much information specifically to this issue on Oracle. Would appreciate if someone could share their experience on this.