Indeed, this bug is sometimes a huge issue with a lot of villagers inactive time.
Below is what I wrote during the beta about it (post does not exist since the release of the game).
Villager queue order bug after dropping resources in the town center
When I ask a villager carrying resources to drop them at the town center (i.e. by explicitly clicking on the town center while the villager carries resources) and then I queue another order (e.g. building a house) before he reaches the town center, the villager drops his resources at the town center and then stops at the town center.
On top of that, this villager does not become idle, even if he does nothing.
This bug does not appear if I ask the villager to drop his resources in a mill, mining/lumber camp and queue a similar order (i.e. the villager will drop his resources and then goes for the next queued order).
- have a town center and a lumber camp
- with a first villager, take a bit of wood
- ask this villager to drop these resources in the town center by right-clicking on the town center
- before the villager reaches the town center, queue another order like building a house
- the villager will deposit its wood at the town center, and not move, without being considered as idle
- test the same procedure with another villager, but deposit the wood in the lumber camp instead of the town center (the villager will deposit his wood, and then go constructing the house, as expected)
This was tested on the third scenario of William Wallace (see picture below).
The villager in the bottom was asked to drop the wood at the town center and to build a house. After dropping the wood, she is not doing anything, but you can see that she still wants to build a house and that I do not have any idle villager (look on the top bar).
The villager on the top correctly builds her house after dropping the wood in the lumber camp.