I use a Zoom R16, and I think the driver is the same. It works fine in Mixcraft. One thing I would look at is if Windows is grabbing the R8 as the default soundcard when you switch it into audio interface mode. I think that might give the result you see - being able to select the Zoom ASIO driver, b...

I have just bought and installed Mixcraft, and I can confirm this is happening with another Air plugin, DB-33. The bottom (where presets are accessed) is cut off.