Midi Guitar Input/Output problem

Using Midi Guitar 2 for MacOS…

I’m using a PG Riff for my interface into a Macbook. When I try to select an input or output method, they both change together to the same I/O no matter how I try to select them individually in the menu: For example, both PG Riff for input AND output, or the USB Audio Codec (for my external speakers/monitors) for both. Obviously I’d like to set the Riff for IN and the Codec/speakers for OUT, and wondering if I’m doing something wrong. (One exception: if I select the Macbook internal speaker it will let me split the I and O, but listening via those laptop speakers is less than ideal.)

Thanks for any help or ideas.

Use either the headphone out on the PG Riff or the MacBook with a matching audio cable to your monitor speaker system.