Description:

• When I use the MK1 furnace, the items are transfered to a chest but doesn't stack properly (it only stacks when the items are the same number). Leading to a chest filled with items stacked 2 by 2. (I tried other cases and it seems like it only stacks when stacks from the furnace and in the chest are the same amount).

Steps to Reproduce:

• Electric furnace MK1 (No fan, no upgrades) with power from a basic solar panel+coal generator (energy input above and below), single vanilla wood chest (west) for input, single vanilla wood chest (east) for output. (setup with screwdriver for input/output to work, auto push/pull doesn't matter)
• Put raw ores in first chest or in the furnace, watch how the ingots satcks in the output chest.

Technical Information:

• Minecraft : 1.20.1
• Fabric API : fabric-api-0.90.2+1.20.1
• Industrial Revolution : indrev-1.16.7-BETA
• Modpack : Custom, I tried with ores from IR and from other mods and it's the same.

Logs:

• I don't know.

Details:
To try the bug fast, just melt one ore with 2 ingots or more in the output chest (stacked). Ingots stacks if the stack is the same size.