well, one is a trigger and one is not. meaning all the actions tied to "on W down" are going to happen waaay more times than they need to.
If it's not working with on pressed, there's an issue somewhere else..
I'll take a shot in the dark.. are your sprite's collision boxes changing? or is there any other reason the platform behavior is not registering your sprite as on the ground? (see, if this were changing, say, for example, because your collision boxes are changing with the animation frames, then jump will not work as a trigger.. but having it trigger every tick until it registers as on the ground, would get you a jump)