Just found a tiny bug/behavior. I had a storage crate placed down but added no materials to it, so it stayed as a ghost. at one point I had a worker bot run out of battery inside the ghost block. Recharge bots will NOT path find to the bot and will not recharge it. Reminds me of the problem where bots run out of battery in a gate.
WiseMack, I actually had a nice bug with my worker bots and milking cows. They both were just waiting at the milk depot, and as soon as a cow was ready to milk they both went to the same cow and started at the same time, and both got milk. Both DID get placed in storage so for a while I was getting 2 buckets of milk out of each cow.... although after reloading the world I have the same problem you do, I liked getting 2 buckets of milk per cow lol.
Edit: Just made a second milk storage so each bot has its own, and one will still eventually be sitting in front of the milk storage with an empty bucket trying to add. So the problem is happening when they meet at the cow not the storage.