When i press an ability sometimes the game takes some time to use it and then uses it late.

Like when i press Q on Zed, it shows the quick cast indicator even after i pressed Q and then he starts his cast time then he throws q wherever my mouse is. So if i were to press Q at blue buff and then right click towards midlane Zed would not throw his q for a couple of seconds then throw it towards midlane. This seems to also happen with point and click abilities where it shows the quick cast indicator then then uses the ability late. This is super annoying especially playing a caster champ. Is there a fix?