hushed fulcrum
when they're stocking up, they'll either take the bow and stand there instead of getting food or going to the rally point, or if they already have a bow they'll stand somewhere nearby. if they're not enlisted, they'll take the bow and stand there with the 'swapping equipment' icon over their heads.
this happens with any combination of assignments, including when only a bow is assigned in either primary or secondary. it also doesn't affect every villager - I have four archers, and one of them took his bow and went off to work normally, while the other three were stuck. It's been happening throughout my game, but until now it could be fixed by taking their bow and either giving it back or putting it in the weapon barn, but that isn't working anymore.
I haven't researched or made any shields or two handers yet, so I can't check if this happens for other back slot weapons or not.
icy shard
valid hearth