I bought a Pegasus R32 from Apple. I have an older Pegasus chained to it. Sometimes the unit will not turn off, no matter what. I shut down the Mac and it continues to run. I try to manually turn it off, but nothing doing. I have resorted to unplugging it and then plugging it back in. I'd like to know what the problem is. I have a ton of work stored on it and don't want to lose any of it. 

I'm using a Mac Studio, if that matters.