[3.0.0] Creating a kit with /kit create causes the second item to fill the kit container

[lelmc]

Nucleus Version

3.0.0-BETA3

Sponge Version

spongeforge-1.16.5-36.2.5-8.1.0-RC1141

Java Version

java8

Plugins/Mods

ForgePlaceholderAPI-Forge-2.0.4-1.16.5.jar
griefdefender-spongeforge-api8-2.1.7-TEST1.jar
LuckPerms-Sponge-5.4.25.jar
Nucleus-3.0.0-BETA3-MC1.16.5-SpongeAPI8.1-plugin.jar
Pixelmon-1.16.5-9.0.1-server.jar

Describe the bug

When using /kit create name to create a kit Putting a second item into the kit container fills the entire container

[SuperNerdyNate]

I'm having the same issue, except it goes a bit further. Any kit made will output an entire hotbar of the item put in it (no matter how few was put in). Additionally, kits aren't being loaded after server restart (they simply don't exist and have to be remade, even using /nucleus reload doesn't load up the kits).

My plugins list is about the same as well, save that I'm using Beta6

[dualspiral]

This is weird. I'm testing it now and I'm concerned that this might be a Sponge problem, as I use the API-8 InventoryMenu system with one listener, on closing the inventory.

I'm trying to take a deeper look but this might a bit more time to resolve.