Issues requiring a restart of the MRCC

[House de Kris]

Sounds like you are describing stuck notes. To clear out stuck notes, typical MIDI nomenclature is to push the Panic button. Panic will issue all notes off to connected instruments, making them quiet. On the MRCC, to hit the Panic button, just press and hold the Shift and press the Encoder button. This is found on page 19 of the manual. Shouldn't have to power cycle your instruments or MRCC.