Twitch Ult not letting him deal dmg to structure

Twice in a game, while twitch ultimate was active, i was unable to deal damage to an inhibitor, and the nexus. I was the only person around the nexus, so I know for a fact i was attacking it and not something else. The auto attack animations were made and bullets were hitting the structure but no damage was being dealt. Would have easily won that 67 min game if not for bug.