They made changes to ui and menu buttons. They removed split option then added it back broken. You cannot split stack from one inventory to another. The split stack(if there is room) will be split in the original inventory. Then you have to move the split to the other inventory.
…and yes the quick stack was added and the give all happens when you hit quick stack twice. However as you have noticed, thw hot key is mapped to multiple things. For some reason my hotkey for repair and quick stack are the same in a crafting menu.