SoundList go missing in Drum editor

I have annoying problem when editing drum editor.
I often missing the soundlist on between inspector and note display.
It was fixed after reseting Default.xml in Application Data Folder.
But a short time later, this problem show up again.

I wiped out preference from cover to cover but no resulting.

Can someone please let me know how to salvage the missing soundlist in drumeditor?
nosound.png