What are the triggers of "Copy Ownership to Next Year"?

Summary:

We want to know what triggers the prompt to run "Copy Ownership to Next Year". Why does a new entity addition sometimes trigger the prompt and sometimes not?

Content (please ensure you mask any confidential information):

There are 2 entity hierarchy, a main one and an alternative one. We always lock the main hierarchy upto the latest year. In the alternative hierarchy, there is an adjustment entity, and we usually have late adjustment to it. Hence, we do not lock it or will only lock it in later months during the year.
What we observe previously is that whenever there is a new entity added, system triggers "Recompute Ownership". Since the alternative hierarchy is not locked, it prompts us to "Recompute Ownership" for the adjustment entity for previous years. Once we run "Recompute Ownership", it triggers the "Copy Ownership to Next Year". And this requires us to unlock the main hierarchy, which is very undesirable.