Default Ok google not working GT-I9505

Whenever I say OK Google it doesn't work even though the hotword detection is ticked on. I know its common and i've read other sites that theirs dont work as well on their galaxy s4 no matter the unit. I compared to my friends GT-I9300 and his works fine.

Im just wondering if anyone has an idea when they will fix this?

Sent from my GT-I9505 using XDA Premium 4 mobile app