Cant teleport on minions

I have been having a problem for some time and I thought it would have worked itself out by now but it has not.

I use teleport a lot and from the time I started playing this game to now I have not once been able to teleport onto minions. I can teleport on towers, wards and Teemos mushrooms but for some reason I cannot teleport on minions. My friend told me a few times to teleport on the minion to get close but I told him I couldnt. I was constantly clicking on the minions furiously but to no avail. He said that I should be able to do that but apparently I ran into some kind of bug. Everyone else I have ever played with can do it but for some reason I cannot.

What could be causing this issue?