[Gameplay] Surging Tides (Nami)

Found out Nami's passive has either a mistake in description or it's simpy bugged. When my spells were supposed to give +120 movement speed, they were giving ~70 to allied Master Yi, ~80 to Fiora etc. Also, when casting it on myself I was only getting the base speed without ap bonus. Here are screens from the same game but later. As you can see, my passive was supposed to give 150 movement speed and Fiora went from 409 to 514 so the bonus speed was 105. What happened to 45 speed?