Azir ultimate bug

Greetings,

Am I the only one encountering Azir's R is bugged sometimes ? The problem is at a recent game, I respawned at Nexus, full mana, R ready to use. I ran to bot tower where our support was pushed under the tower by Leona and Ashe, and when I got there and prepared to ult them out, it just didn't want to work. I tried four times, and it didn't execute my ultimate and our beloved Soraka died. Can you please check it out and fix? It's not the first time happened to me. Thanks.