The Drag & Drop from items in the inventorys only works if you don't release the mouse button, and pull over the item to the slot. If you just click on it and move the cursor, the item do not get selected.
MC-92404
Minecraft on XWayland: Drag&Drop working very bad
Resolved
Awaiting Response
0
(Unassigned)
Unconfirmed
Minecraft 15w44b, Minecraft 15w45a, Minecraft 1.9.1, Minecraft 1.9.2
Retrieved
Is this still an issue in the most recent versions (currently that is 1.10.2, or 16w42a) of Minecraft? If so, please update the affected versions and help us keeping this ticket updated from time to time. If you are the owner/reporter of this ticket, you can modify the affected version(s) yourself.