Not sure if anyone has reported this or if it's intended, but I've found that if you animation cancel Assassin's Will with a dodge roll then the Bow makes the sound, gets consumed but doesn't fire.

Edit: block cancelling and abilities also cause this. It seems as though if I press it to fire but the bow animation doesn't completely finish then it won't fire.

I isolated it using the in-game combat text and DPS results but just to be certain, I proc'd the Bow during one round of combat, waited for combat to finish and then fired only the Bow using the aforementioned process but I didn't enter combat nor did any damage show up.

This is on PS4/EU.