[gameplay] Ekko Ult not doing damage or healing

I just played a game with Ekko, base skin, where my ult teleported me back 4 seconds, but failed to heal me and seemed to do no damage every time I used it. No idea about replication, the champions on my team were Ezreal, Nautilus, Diana, and Xerath. The enemy team was Yi, Ahri, Pantheon, Jinx, and Morgana. The Yi on the other team kept lying that he was "timing his Q to it" (he wasn't, I was timing my ult to start after his Q ended), but there was one point where I ulted right on top of enemy Jinx and got no heal and did no damage, with no other champions from either team nearby.