Specific items consistently "rubber band" when moved within inventories on 1.12.2 servers

[Keeg-Turner]

General Information

ViaVersion Dump URL: https://dump.viaversion.com/3fe1595c83f324bedebe0e6b98104d70e1668acf9438d1b3219be2c74e5dfdd7
Game log URL: https://mclo.gs/m5Hu2C7

Bug Description

When playing on a 1.12.2 server, specific types of items are prone to rubber banding when moved manually, or using an inventory manager like Inventory Profiles Next; this is particularly noticeable/problematic in the latter case because it completely undoes any bulk sorting or moving operations if any of the items in question are involved. The main items currently affected are the following:

• Seemingly all items that can be damaged (tools/weapons/armour) except for leather armour
• Written Books
• Maps

Notably, this seems to be negated for most/all of these items if they are named in an anvil or enchanted, where applicable.

I've used various versions of ViaFabricPlus and MultiConnect over the past few years, and noticed that the selection of items affected by this issue has varied across versions. If I recall correctly, in the past year or so, the selection of items to which this applied in ViaFabricPlus was much larger and seemingly random, though I unfortunately don't remember the specific version(s) when this changed (might've been around the time of the major rewrite).

I was also able to reproduce this bug both on the latest 4.0.1 release and the latest 4.0.2 snapshot.

Steps to Reproduce

1. Make a Minecraft installation that includes ViaFabricPlus, Inventory Profiles Next, and their dependencies
2. Connect to minecraftonline.com on version 1.12.2
3. Fill a chest with a variety of items, including one or several of the ones listed above
4. Press the Sort Inventory button (shaped like a Z)
5. Observe how the assortment of items briefly appears to be sorted, but then returns to being unsorted. One of the problematic items will also be picked up
6. If your inventory has plenty of space, you can also try holding Shift and the pressing the Move Matching Items button (shaped like a ⬐); the same kind of issue will occur, where the items appear to move, but then some/all of them get sent back to the chest, and one of the problematic items is picked up.

Expected Behavior

Mods like Inventory Profiles Next should be able to freely sort and move all items as expected without any rubber banding.