If possible please give some inputs on where to check or what data might be missing ,cases why it is not getting updated.
Issue is when TO is confirmed for Inbound Delivery HU quantity is not getting updated and WM quantity is getting updated.
This should not happen...both should get updated else this will show difference in quantity.
Table for WM quantity = LQUA
Table for HU quantity = VEKP (Header) and VEPO (Item.)