Okay, so, I would like to address an issue to you with this. I use HALion Sonic SE 3 as a VST3i on REAPER. It is only sending input to channel 16 instead of the channel that I want it to send to. How do y’all or I fix this?
I don’t use Reaper, but you should be able to right click the track in Reaper’s track list to define your MIDI inputs. If you’re using a hardware MIDI keyboard/controller, please make sure that it’s setup to send MIDI output to the correct channel.