Turn On your MODX8 (it should be powered On before you open Logic Pro).
When you have good working connection between your MODX8 and your computer, you will see a bright blue USB icon on the top line of the MODX screen.
Press [UTILITY]
Touch “Settings” > ”MIDI I/O” > make sure “MIDI I/O” = USB (green)

Connect the Main L/R Outputs of the MODX8 to a quality stereo sound system. Play the MODX8 and ensure great sound.

The MODX8 should be connected directly to an available USB port on your computer using the appropriate USB cable and adapter. (You have a Mac so you have plenty of adapters).

On the computer... You need to have downloaded and installed the following items from the official MODX Download Page:
__ Yamaha Steinberg USB Driver for Mac version 2.0.3
__ MODX CONNECT version 1.1.0 for Mac
__ If you have not updated the firmware Operating System of your MODX, download and install version 2.51

Once powered on and connected via USB to your computer... go to System Preferences > Sound > the MODX should appear as an available Sound device. Make sure.

Launch Logic Pro.

Please verify each step above and let us know... no need to go any deeper until these things are accomplished. Let us know.

I did everything you said. When I hooked it up, I got this weird continuous noise. This kept up until I turned off the direct monitor in Audio I/O section.
I tried to record an audition of CFX & Orch 2, but nothing would record.

I did everything you said. When I hooked it up, I got this weird continuous noise. This kept up until I turned off the direct monitor in Audio I/O section.
I tried to record an audition of CFX & Orch 2, but nothing would record.

I did NOT give you enough information to get any kind of signal through the system. Logic Pro like most DAW can record MIDI or Audio. You don’t tell us which you recorded, the setup for MIDI is going to be different from the setup to record Audio.

Which are you attempting to record MIDI or Audio? I purposefully stopped before setting up Tracks of any kind. If you’re sure you have all these things installed properly then let’s move forward...

Your MODX is setup and ready to deliver MIDI and Audio to your computer... for additional help setting up Logic Pro please see the following:
MONTAGE and Logic Pro X
Although written for the MONTAGE you can get a lot from this in terms of working with Logic Pro
We should mention the MODX has ten USB Outputs are as follows:
USB Main L/R
USB 1/2
USB 3/4
USB 5/6
USB 7/8

They may appear in LogicPro as just 1/2, 3/4, 5/6, 7/8, 9/10.
Just know that the first two are the Main L/R