Mirage Playing Errors Sustained then Stopped All

I booted up my Mirage, loaded sound samples Upper and Lower, then did a chromatic scale to test each key. When I got to C3, it sustained the note and didn’t stop until I turned off the board and rebooted everything. Second attempt, started playing the scale again and midway all sounds ceased. I have no idea why this occurred. Hoping for someone to provide a simple explanation, thanks!