Garrisoned villagers in TC not shooting?

I just had a game where i had 15 villagers garrisoned in my TC but they would not shoot at any enemy which were basically standing next to my TC. (besides the default arrow which is always shot by TC). At one point it were more arrows (5-6) but then it died down to lesser arrows again (3-4). Am i missing anything here? I can provide a clip of it if necessary.
This went one for roughly 2 minutes without any idea what was going on.