Halion Volume issue

Hi. I have a Korg digital piano. I record into Cubase with a UM-one Midi. I record with an audio playback, then mix that down to one track. The Halion instrument playback is very quiet, yet if I reroute the output to my Korg, the volume is just fine. I’ve tried everything, including manipulating the velocities in the Key Editor, but when I do that I get too much velocity and not enough volume output.

Thanks for any help.