SOH Quantity Lingering in STAGE Subinventory

Our Supply Chain team has been monitoring a quantity from our Stock on Hand for an item that has been lingering for a period of time within our Staging subinventory. Typically, this SOH quantity would normally be set to automatically transition to our main STORE subinventory following its corresponding pick tickets being confirmed as part of the process. However, the SOH quantity in question has remained in the STAGE subinventory (per the Manage Item Quantities screen) for over a month now:

We verified that all open picks have been confirmed.

Are there any ideas on what else could be checked to determine what could be causing this SOH quantity to linger within STAGE?