It's been a month with no answer, so I'll try again.
I've got a Macbook Pro running Sonoma.
My analog audio has suddenly stopped reaching Studio One from my USB96.
I'm testing using an analog output from a MIDI keyboard and a microphone. I am able to record both inputs using GarageBand, QuickTime, and Mac Voice Memos. Also, the input level for the Mac System Sound responds to both the mic and analog keyboard inputs.
But Studio One doesn't get either channel of analog input. It does see the MIDI input from my keyboard (I can record into an instrument track), and I can hear both analog and instrument channels on song playback through headphones plugged into the USB96.
This worked until about a month ago.
I've unplugged/replugged every connector and restarted my laptop -- nothing helps.