@Peter and @Damir I'm on 3.8.2. Problem seems to have resolved - not sure what happened.
I had originally tried to assign actions using the detect feature in the "Assign Actions" menu. The app was not recognizing the button presses on the BT-105. I then went into the Information menu on the keyboard airturn menu and tried to assign actions there - didn't work. I confirmed the BT105 was connected and operating in Onsong, and posted this note.
This morning, I tried again - went into the "Assign Actions" menu and the button presses WERE detected. I assigned the scrolls as needed (interestingly, the BT105 left pedal was PORT 1 - and the right pedal was PORT 3).
Thank you both!!