Midi fader problems

I programmed drums and was using Groove Agent. I had all of the midi drums on separate midi channels. I usually use the audio fader to adjust the levels of each drum (they’re assigned to separate outputs). Accidentally, I brought up the midi fader to adjust the level of a drum and after I moved it, I realized my mistake and put it back. Normally, the midi fader shows up with it’s fader at 0 and the pan all the way to the left; it’s says ‘off’. Turns out that once this is moved, there is no way to undo this…and it affects all the midi faders together.
So when I pulled the fader down to zero, I can’t hear any drums; and when I turn up the midi fader, with the pan back to ‘off’, everything comes out of the left side. I had to delete the midi channels (I kept the midi data) and the instrument and start over because every subsequent midi track I created responded the same.
What could this possibly be used for? And is there a way to undo or reset something to put things back. I tried the ‘reset midi’ and it did nothing. The manual is of no use if you don’t know what the solution is called.
Any helps would be appreciated.

In Groove Agent, the MIDI Volume and Pan affect the whole MIDI Channel (or in other words, the whole drumkit like you’ve experienced). Your previous audio fader and pan settings are left unchanged, so it’s easy to go back.

The default MIDI settings for all Steinberg instruments is 127 Volume and “C” Pan. Some third party instruments may default to 100 Volume.