It’s going to be an OS issue. My x500 doesn’t move around much. It has never left my home, and if it’s ever moved, we’re talking 2 feet. The OS glitch with the mixer was originally an issue at the release of the unit that required a patch. I think the OS portion of the mixer is corrupted beyond what the user can do, and would require a software fix from Casio. They can’t fix it without physically having the board also. They wouldn’t be able to reproduce the problem on their end because the data corruption is specific to my keyboard. I’m still thinking these new models don’t like being unplugged for long periods of time.

Sqk