I reply to myself as I identified, that the issue seems to be in my hardware soundmodule Ketron SD1000.
Biab put it somehow in that "harmony mode" and in other music programs (VArranger V2) I also have everything playing on harmonies :-(

Does anyone have an idea how that came? Maybe also how to fix it? Restarting SD1000 left this awkward behaviour active.

Thanks in advance!

Cheers
Stefan


DAW: Studio One 6.2 Pro
Interfaces: StudioLive AR12c, Scarlett 8i6
Windows 11 Professional
AMD Ryzen 9 4900H, 16GB, 3,30 GHz