MIDI device not detected

I recently purchased a soundcard (Roland Quad-capture UA55) to pair with my digital piano (which is Roland FP-90) in order to utilise piano VSTs. I have followed thoroughly the instructions and everything seems to work correctly, except the MIDI studio part. After installing the driver on Roland's website, my Macbook does recognise it, as I see its name on the side bar of the audio settings (I can select to input, output, play sound effects through the UA55), but I cannot get it to appear on the MIDI studio as it's supposed to be, even after rescanning multiple times. I have tried uninstalling and reinstalling the driver without the UA55 connected to my Mac during installation but the problem still persists. What's strange is that while Roland's website suggests disconnecting and reconnecting the USB cable, that immediately forces my Mac to restart every time (I don't know whether this is UA55's defect or the driver's). Anyway, my setup is like this: I connect one end of the 5-pin MIDI cable to the MIDI OUT port of my FP-90, the other end to the MIDI IN of my soundcard. Is that correct?