Destroyers vs Subs: attack button doesn't work

I had an enemy sub attacking one of my subs. Sent in a near by destroyer to help out using the Attack button. The destroyer held off at range and started bombarding but no damage was happening to the enemy sub. After a couple of hours fussing around I found you had to manually move the destroyer to practically on top of the enemy sub to do damage. They really need to fix this: using the attack button, destroyers need to move to the proper distance to actually attack subs.