Sometimes particular spells don't give vision

In the last few patches there is a very annoying bug: spells that are supposed to give vision of the target sometimes don't.

Eg.: Lee Sin Q hits and even though you see that you can jump, the target is not revealed. Other example Caitlyn trap: enemy walks into it takes the damage and gets snared but no vision is given.

They don't happen very often, but it needs to be fixed, because they are very annoying, especially when all we need is vision of our enemy.

A video I found on youtube about the Caitlyn trap bug: https://www.youtube.com/watch?v=kHcaXUEzyPE .