How do I de-couple Cubase from my UR44 interface?

I have the Steinberg UR44 interface (as well as a Yamaha MOFX). In theory the are all supposed to interact but that is a cruel joke. I keep getting audio tracks in Cubase that no longer receive input from the UR44. I have to create a new track with the same i/o settings each time - the dead one never works again. The UR44 interfaces with Cubase - it shows up as a hardware device in the Cubase 8 mixer. I think there is some sort of driver that is loaded but I’m not sure. Anyone have any ideas? Thanks!

note: The MOFX/Cubase interaction is another nightmare! I thought I was choosing well going all Yamaha. :imp: