[GAMEPLAY] Nami ult bug?

Unfortunately, I didn't get to record this, however in my last ranked game as Nami, my ult has bugged and not knocked anyone up. As I was lagging at the time, I was unsure if it was just due to lag, however multiple team members were confused as well as to why it was happening. No one on the opposing team had a Banshee's Veil and it was quite frustrating for it to not take any effect lol. I figured it couldn't be just be lag if other people saw the wave and it not take any effect.

Unsure if anyone else has experienced this either, though I figured I'd report it as it happened multiple times (>2-3) during the game.