This only reflects my personal experience. Your mileage may vary. But nonetheless, might help someone.
When I got my MiniLab3 it was supplied with a USB A to USB C cable. Works great with my MacMini which has some USB A ports. However.. my 2016 MacBook Pro has only USB C ports. Connecting the MiniLab3 to these USB C ports, using an Apple A to C adapter, powers up the ML3 OK but that's as far as it goes. The MacBooks MIDI Setup fails to register any new device and so Arturia Midi Midi Control won't see it either. The A to C connect, with the Apple branded A to C adapter, has been tested by connecting my Keylab 61 Mk2 to the MacBook without issues.
So what worked? Replacing the supplied USB C to A with an (Apple in my case) USB C to C cable. Bingo. ML3 powered and instantly recognised So.. there is something 'not quite right' with the MiniLab3 USBC port when connected via a C to A adapter. Just get a C to C cable. Caveat Emptor.
