ive had something similar to happen where channel 11 12 13 wouldn’t mute , I couldn’t figure out how to fix it so I did a factory reset. I thought maybe it was my routing setup but couldn’t track it down. its happened 2 times so far. that was with firmware 1.2.2 all the way to 1.3.2. . I thought it was my error so I never posted it. but I still can’t explain what happened, they were on different subgroups guitar one group and vocal one group .guitar channel 10 11 12 and vocals 13 14 15. 10 would mute and 14 15 would mute. haven’t had much trouble since. I know this may not help but it was The only solution I had could come up with at the time.
