I've got a full inventory, holding a few (less than a stack) lapislazuli.

I tried to stock up my inventory by taking lapislazuli out a chest - and held long, to get all.

Result: My Inventory is stocked up to 1 stack of lapislazuli, the chest is empty.
The surplus lapislazuli are lost (forever?)

Expected result: Drop surplus items on floor or leave them in chest.

Same happened with iron ingots, pretty sure it "works" the same way with every item