It seems bugged in this sense:
Using Exact same setup as your 5k bar progie above.
Inventory is ice gloves. It withdraws 27 gold ore, deposits them into the furnace, runs back to bank, gets 27 more gold ore, deposits that into furnace, retrieves bars from furnace with ice gloves, deposits gold bars. [here is the buggy part] once it deposits 27 gold bars, it withdraws 27 more gold ore, closes the bank, opens the bank, deposits the ores it just withdrew out, and goes and retrieves the remaining 27 gold bars from the furnace.
Then it repeats.
It needs to either skip the withdraw/deposit spot OR actually use the ore on the furnace.