Minecraft Username: KMaxwell Brief Description: Stackable items in a backpack will not stack with new items if in your backpack while you log out. Instructions: 1. Put something stackable in your backpack (ore, dirt, glowstone dust, etc) 2. Log out 3. Log back in and try to put new pieces of these items in to the existing part stack in your backpack How many times did you recreate this bug?: 2-3 times Result: Items will not stack Expected Result: Items should stack properly Evidence: None, am unable to video the issue, and screenshots don't really help.
I also tried giving the item, in this case coal ore, to another user (@vwman67) by throwing it to them and it would not stack in their inventory. We were able to re-stack the items by using the /stack command, but not everyone has access to that.
I wonder, are the items changing in id number? Can you do /itemdb while holding the two separate stacks and see if they have the same id number or different?
I just duplicated the bug again in order to try this, and no, there is no change to the item ID # according to /itemdb, both are the same.