catapults that can't attack

[Naokaukodem]

I had this bug that after the attack of some units, my cats couldn't attack the same square. Is that a normal or is this a known bug?

 

[ori]

in BtS there is a damage limit, i.e. siege units can no longer kill defenders but rather can only bring them down to 50% (?) or so - if all defenders are that low they can no longer attack. So no bug here