Azirs Ult is not working

When using Azir's ult it does not push back enemy champions or even stuns them. I had a rare case one time where it worked against a jax but outside of that it has not been working at all and has cost me kills,deaths and Victory's Since my main is Azir you can imagine this is a big problem for me and others. Azir's Ult can save you or help you get that triple kill. Without it Azir is vulnerable and almost unplayable. Please fix this as soon as you can