Video demonstration of the problem: https://www.youtube.com/watch?time_continue=14&v=f7BUdXHRMqQ
Github repo
I've tried a bunch of stuff to resolve this issue, and check what getSlot and slotClick returns, and they seem fine (if i click on a dirt block in my container both of them return that the itemstack contains dirt)
But after those functions get called it grabs from ContainerPlayers inventorySlots, and there the first 9 slots are for armor and crafting, and I'm clueless to the flow and why this is happening.
Container class
Proxy