Why can’t we move stock out of the Staging subinventory when required?

We have stock already present in the Staging subinventory. When attempting to move it to another subinventory (via Miscellaneous Issue or Subinventory Transfer), the system shows zero available quantity or prevents the transfer. This restriction is blocking stock movement out of the Staging subinventory. We need to understand why this is happening and how to enable movement to the required subinventory