[GAMEPLAY] When Fizz dies his ult doesn't attach to the enemy

so i was in a team fight, the last moment before i died i was able to throw my shark , i didn't hit anyone and it stayed on the ground, but the enemy ekko stepped on it, and what was surprising is that the shark didn't attach to him.He stepped in the middle of it and still walked like nothing was under him. but he was knoked up and took some damage when the shark appeared.