Rakan ULT is bugged

I know someone posted this here before, but it didn't got any attention or reply, so here we go. Rakan's ULT hitbox since the release isn't working properly. When u cast it close enough to your target the charm doesn't go off. This happens so often due to fact that after your W you can place yourself right underneath your target. Often enough the Ultimate then won't hit this target and even let's you run through multiple targets without charming them. Bug is easily reproducible in custom game. I don't think this is an intentional 'feature' and if it is, why the hell???
I mean Rakan already has some weird coding in his abilitys but they don't brother me as much as this one.