This desynchronization problem happens when a player clicks stack of items (in this case from the player's inventory) to move them and then pushes CTRL.
Tested for multiple items and for both host and guest. Reproduceable (tested 4 times).
[0.11.3] Desync Issue in Multiplayer
Re: [0.11.3] Desync Issue in Multiplayer
Hello, please report desync problems in version 0.11.5