So, I started a new Town and assigned first the stockpiles and told them to get wood.
After I assinged a farmer to farm silkweed amongst other things, he started bringing some of the silkweed - instead of the assigned stockpile - to the wood-stockpile.
I see my workers doing this often, as well as in other of my towns. It is very distracting when I want to check my inventory for certain stuff without the need of going to the menu for that.
Hope this bug gets a bit of attention, and if then good luck fixing it,