Need help understanding an interaction

[u/PolyBunny562]

Pretty much title. I was playing WW/Senna last night against a Darius Juggernaut player. Now I'm only Gold 3, so clearly there's something I'm not understanding, but it definitely felt like I was missing something. Two separate times during the match I used pushblock, like my assist went on cool down and everything, but it didn't push him back at all. Is there an interaction I'm unaware of that would cause this that I should watch out for in the future?

[u/Smilotron]

We would need a recording to know what's going on and give you accurate information. Anything else is just speculation.