Yeah. I just realised this when I revisited The Tutorial. It seems like TN chose Kasumi's 3H+K as a follow up for a reason. It helps you troubleshoot what you may have done wrong.
If you get launched that means you weren't stagger Escaping fast enough..... if you get put into a lift stun that means you came out of the stun but were caught crouching. Stagger escaping is actually quite easy so the its usually the latter scenario that happens the most.
Yeah that explains why I get hit by it on Normal Hit. I Always thought I let down my guard or something. But it was apparently me being in a crouching guard state when the kick connected.