Nocturne "E" Gameplay

I just played a game with Noc for the first time in a week or so(since before the latest patch). When casting his E, his auto attack stops working. I used to be able to chase a champion, cast E, and continue hitting the champion until E takes effect, then keep attacking. Now, when I cast e, I need to click on the champion again to continue to attack them. It seems to be related to agro of some kind because if I get REALLY close to the person I am attacking, I contoinue to auto attack. I played noc many games last season and this was enough to notice.