I have a midi file that was created on a DAW, using it's own built-in VST, with only one instrument used - a piano. I created a new project and imported the midi file in to Cubase, so I can play the midi data from Cubase to my MODX, using MODX sounds. I was able to create a new Performance using the Init/GM process, and successfully play the imported midi file on the MODX from Cubase, but the sound being generated was the default Concert Grand that appears in the first 8 parts of the GM/Init setup. I changed Part 1 to a different Piano sound that I actually want to use to play the midi file, and first time through, I got exactly what I was looking for, UNTIL I press stop in Cubase, at which point, Part 1 immediately goes back to the default Concert Grand. How do I keep the selected part assigned to each midi channel without the Part reverting back to the default Concert Grand each time I stop Cubase? I watched a bunch of videos on this topic, and all are geared towards making your own recording to midi first, but I was unable to find any that started with a midi file from an external source.
Found the solution - in case anyone else has the same problem:
With performance created by using Init/GM active, press Utility button, then choose "Advanced" menu from left side of panel, then change midi I/O mode to either Single or Hybrid. The problem noted in the original post is caused by the midi I/O mode being set to Multi.