Same fleet I have used at least 3 times on Homeworlds (with the stronger ODS), now used on a colonised planet with one ODS. It killed one of the ships and worst thing my fleet did not fire (I assume as one ship was destroyed).
I can only think it is a bug that my fleet did not fire, and it had full ammo and HP. Btw this fleet was almost completely destroyed, even Homeworld has not done this. Thanks.