GAME PLAY- BUG- Thresh's Ult Prevents teammate Ults

So i have seen this happen twice now. and the only common denominator is that it happens when inside or being effected by a fellow thresh's ult.

#1-My teammmate thresh laid his Box down, and our garen ulted a Katarina, the graphic went off..and his ability went on CD..but no damage was delivered to Kat.

#2- My teammate thresh laid his box down, and i used my Enchanted frost arrrow (ashe's ult) on the enemy support and adc who was trapped inside Thresh's ult...the Arrow went right through the champions. Even the enemy team /all chat "wtf...was that?"

Riot, please look into these issues....they are real. Has anyone else noticed this?

Thanks. EddieCotton