I get this too - I set up a group of furnaces that are logs via a hopper loop, and one of the furnaces is always skipped entirely.
I attached two screenshots of a simple system to replicate the bug: There are four furnaces in a 2x2 square. Above them, four hoppers feeding into the furnaces. Above those hoppers are four more hoppers, arranged in a loop (travelling counter-clockwise). The chest feeds into an arbitrary hopper. What should happen is that if all four furnaces have no logs in them, logs from the chest should flow into all four furnaces one at a time, first filling up the furnace, then filling up the hopper that feeds directly into the furnace (assuming the wiki is correct). Instead, one of the furnaces in the square is skipped (in my images, it's the second in the loop). I wasn't able to show it in the images, but if you look at the inventory of a hopper in the loop, you can see logs flashing through it - unlike a normal hopper feed, where one item remains in the hopper consistently. This doesn't occur in any of the other hoppers (the one directly under the chest, or the four that feed directly into the furnaces). If you use a comparator to check the capacity of one of the hoppers in the loop, it flashes on and off. (For me) this seems to occur primarily with hoppers that are pointing sideways into a block with inventory, but also have a hopper underneath them. Unloading and reloading the chunk doesn't do anything to help, though - nor does checking any of the inventories involved.
Monch
I get this too - I set up a group of furnaces that are logs via a hopper loop, and one of the furnaces is always skipped entirely.
I attached two screenshots of a simple system to replicate the bug:
There are four furnaces in a 2x2 square. Above them, four hoppers feeding into the furnaces. Above those hoppers are four more hoppers, arranged in a loop (travelling counter-clockwise). The chest feeds into an arbitrary hopper. What should happen is that if all four furnaces have no logs in them, logs from the chest should flow into all four furnaces one at a time, first filling up the furnace, then filling up the hopper that feeds directly into the furnace (assuming the wiki is correct). Instead, one of the furnaces in the square is skipped (in my images, it's the second in the loop). I wasn't able to show it in the images, but if you look at the inventory of a hopper in the loop, you can see logs flashing through it - unlike a normal hopper feed, where one item remains in the hopper consistently. This doesn't occur in any of the other hoppers (the one directly under the chest, or the four that feed directly into the furnaces). If you use a comparator to check the capacity of one of the hoppers in the loop, it flashes on and off. (For me) this seems to occur primarily with hoppers that are pointing sideways into a block with inventory, but also have a hopper underneath them. Unloading and reloading the chunk doesn't do anything to help, though - nor does checking any of the inventories involved.