A cooked food left in stove's UI (potentially other food crafting stations or machines in general) if left to spoil into mold, that mold will multiply within the UI when attempted to be moved around.
To recreate: place cookable meat into a stove -> cook it all so cooked meat occupies all the slots (don't move it yet) -> leave it to spoil -> attemp to move the mold around, combine into stacks, you'll it seemingly multiplying
A cooked food left in stove's UI (potentially other food crafting stations or machines in general) if left to spoil into mold, that mold will multiply within the UI when attempted to be moved around.
To recreate: place cookable meat into a stove -> cook it all so cooked meat occupies all the slots (don't move it yet) -> leave it to spoil -> attemp to move the mold around, combine into stacks, you'll it seemingly multiplying