Rekordbox driver for 2x CDJ400 (audio asio issue)

I am having trouble with the right driver for sending audio to my DJM800 using Rekordbox 5 and two CDJ400.

 

I am using:
MacBook Pro 2016 with the latest update (macOS Mojave version 10.14.3)

A USB-C to 4 USB input adapter for multiple USB devices

Latest version of Rekordbox

 

CDJ400 have a 1.30 version of firmware

 

Two weeks ago I bought 2 CDJ400's after I saw how easy it was to connect them to rekordbox and send audio to a mixer. I purchased the BASE PLAN for Rekordbox as well to use this function.

 

Right now I am having the issue with the audio driver. It only allows me to select one of the 2 CDJ400's as a driver. When selecting the AUDIO OUTPUT, it allows me the same; only one output CDJ (1) or CDJ (2) is able to be used as an output. 

 

The fix should be: both CDJ's should be able to be chosen for both outputs: ouput 1: CDJ400 (1) and output 2: CDJ400 (2).

 

What am I doing wrong? Looking forward to your assist.

 

Best regards,

 

Mark de Graaff