question.md

I'm trying to add a stack-crushing feature to my anvil crushing recipes mod and I'm getting an issue I *really* don't understand.
First a basic explanation:
- the mod lets you define recipes with block or entity ingredients and that can output in a variety of ways
- I'm adding a feature that lets you specify a lit of ingredients, all of which must be crushed to obtain the output
- to accomplish this, I've:
    - mixin'ed to `FallingBlockEntity`, saving a `crushedList` that I save/retrieve by mixing into `writeCustomDataToTag` and `readCustomDataFromTag`
    - mixin'ed to `AnvilBlock`, implementing `BlockEntityProvider` (I've created an `AvnilBlockEntity` class)

Now the issue:
Somehow my `crushedList` is getting passed between different anvils or falling anvils.
This makes recipes not work consistently when testing a single anvil, and makes trying to do multiple anvil crushing recipes at once consistently fail.

I've double checked my mixin classes and I've made nothing static.
I've also double checked that my `AnvilBlockEntity` is being removed the same way other BEs are removed (or at least the same removal code is reached).

Here are
- `AnvilBlockMixin` https://gitlab.com/supersaiyansubtlety/anvil_crushing_recipes/-/blob/stack-crushing-feature/src/main/java/net/sssubtlety/anvil_crushing_recipes/mixin/AnvilBlockMixin.java
- `FallingBlockEntityMixin` https://gitlab.com/supersaiyansubtlety/anvil_crushing_recipes/-/blob/stack-crushing-feature/src/main/java/net/sssubtlety/anvil_crushing_recipes/mixin/FallingBlockEntityMixin.java
- `AnvilCrushingRecipe` https://gitlab.com/supersaiyansubtlety/anvil_crushing_recipes/-/blob/stack-crushing-feature/src/main/java/net/sssubtlety/anvil_crushing_recipes/AnvilCrushingRecipe.java

also, here's a test world where I have a setup to drop multiple anvils at once
https://gitlab.com/supersaiyansubtlety/anvil_crushing_recipes/-/tree/stack-crushing-feature/run-client/saves/1_16_3

Any pointers/suggestions would be appreciated.