MIDI + SoftSynth(Ableton)

[Jesse Johannesen]

Oh hey, that's definitely strange. Can you play the notes with the push and hear them on the output? Is the VU meter for the Ableton channel strip showing audio volume? The only thing I can think of off the top of my head to check is that you have the channels monitoring incoming midi (I forget if you have to do that separately from setting the MIDI channel) and/or recording armed, and that the velocity settings in the Settings Page 3/3 are non-zero values.

Hopefully it's one of those things, but if not let me know and I'll help you dig a little deeper into it.
Best,
Jesse