Version 0.0.63
Found a reproducible bug where if the npc order hasn't been fulfilled and they start walking away from the shop, you can put their order on the counter and they will stop and not despawn. you can even take their order to them and they will accept it and leave, or they will stay and not despawn.
Also for a bit of fun after it got stuck I decided to try smelting the leaning tower of copper, however I was dissapointed to find that the furnace has a maximum height that it can smelt to :( . As can be seen below.