Copper Golems stop moving

I have tried patiently to get a copper golem storage system to work. They are SO unreliable, that it’s almost impossible. I must have made 20-30 different versions now. Currently the problem is this: I have a golem sitting in a 1x1x1 spot (cause they need that to avoid being idjits and to be sufficiently fast). It can reach the copper chest, 3 chests that have redstone filters attached, and then a 4th chest which is a hand-off to the next copper golem, one section over. So far, so good. In theory, this should work just fine, but now they’ve started just sitting there. All of a sudden, they stop picking up items from the copper chest. Completely at random. Sometimes they work just fine for days, and sometimes they stop working after 5 minutes. At the moment, I “solve it”, by opening up the space to them, punch them once with my hand, and then close it up again. I guess violence incites action for them? Probably it’s just yet another issue with their buggy path finding, I’d guess.
The idea with them is so fun. But in reality, they are a gimick or a building block once they become statues. They are FAAAAR too buggy, laggy and unreliable to use for anything meaningful regarding sorting.