Jhin Bug - Issues with Deadly Flourish Passive

Hi all,

I've been playing Jhin recently, and in my last game I noticed a few issues with the passive and active of Deadly Flourish. As you may or may not know, the ability is as follows:

• DEADLY FLOURISH PASSIVE - CAUGHT OUT: Enemy champions damaged by Jhin's basic attacks, his allies, or inside a blooming Captive Audience Lotus Trap are marked for 4 seconds.

• ACTIVE: After a delay, Jhin fires a shot in the target direction, stopping at the first enemy champion it collides with and dealing physical damage.

>> Damaging a Caught Out champion roots them and grants Jhin Every Moment Matters' movement speed. <<

I have noticed three issues at the moment, based upon my last game:

1. People are returning to lane with my mark on them, after taking no damage whatsoever. This mark remains even after I have damaged them and triggered the mark.
2. I damage a person, and although I have applied a mark, Deadly Flourish doesn't stun them. It bounces off like someone has a banshee's veil.
3. Damage done by other players, although triggering the mark, doesn't allow me to stun them.

The last two are quite rare, but the first one has occurred across multiple champions in one game. Any thought/experiences similar to mine guys and gals?