Gameplay - Sona bug

I was playing a ranked game and something bizarre happened near the beginning that cost us the lane. I was playing lux, and when I tried to snare Sona with my Q it passed right through her unaffecting her. Then a few seconds later when my brother, playing as Vayne, tried to use his E to stun Sona, it wouldn't allow him to target her. This was early game so there were no items that may have caused this and the only other champion around was Kalista. Sona also had the DJ Sona skin incase that makes a difference. It may have been a one time thing, but if it is a bug I hope it gets worked out. Thanks.