It would be nice if you could fix this or change this.
When using mystery crate items are moved to a different slot rather than taking up the slot the mystery crate was in. In the images below the diamond pickaxe is a crate that gives a diamond pickaxe. The first image is the crate and when you right-click to open it you a given a diamond pickaxe which is moved to the second slot rather than filling the first slot.
It would be nice if you could fix this or change this.
When using mystery crate items are moved to a different slot rather than taking up the slot the mystery crate was in. In the images below the diamond pickaxe is a crate that gives a diamond pickaxe. The first image is the crate and when you right-click to open it you a given a diamond pickaxe which is moved to the second slot rather than filling the first slot.