how to disable audio signal through ur44 when unplugged

Hello all,

My UR44 is on but my computer is off and the usb to the interface is unplugged. Sound from my instrument is STILL going through the speakers?! Any idea on how I can fix this? My biggest problem is opening it in Bias FX and hearing both a clean sound and distorted sound. When I open Cubase the audio stops until I click the monitor button on the track, so that is fine. It has worked before on Bias FX (I even played live with it and it was fine). I am using windows 10. Can anyone help?