[Gameplay] Happened more than once that Fizz ult didn't latch in a specific circumstance.

Twice, while playing Fizz I would use my ult on a spot where a champion was currently either not in or untargetable in. The first was a Katarina. She used Zhonya's and I threw Chum the Waters directly on top of her (As in it stayed on the ground right where she was untargetable.) The second she got out of Zhonya's she was able to Shunpo out of the ult WITHOUT it latching. The ult came up after the shunpo and not right as she shunpo'd. This let her get away and makes no sense that you should be able to have it not latch when that happens. The second time I was against a LeBlanc. She used Distortion towards me and I placed Chum the Waters directly on top of the "return platform." When she returned, instead of latching on, she was able to use a second Distortion to get out before Chum the Waters even erupted. First Distortion is a dash, so essentially she dashed over my ult at the very beginning of the cast, but second she was able to live because Chum the Waters didn't latch on like it was supposed to. I know most people don't care since they all hate Fizz, but for the Fizz mains, please explain/fix this.