Can someone please help me with Xenomorph.

Yeah, Xeno is pretty weird. I think the biggest help for me was aiming up a little, and then dragging down if needed. The hitbox acts kinda like a rock tied to a rope: it doesn't go perfectly straight, but kinda goes down while going forward (not my analogy, that was from Otz).

The best comparison in terms of another Killer is Nemesis. His tentacle can be moved side to side and still register a hit, and Xeno's tail is like that but vertical.

Yeah no problem! I hate that I couldn't help out more but regardless, I'm happy to have tried lol