OK, so there we have the problem. The Airturn acts as a bluetooth keyboard. So macOS intercepts all key presses before they are sent to the app. Now cursor up and down (in mode 2) is always interpreted by macOS and never sent to the app. I guess this happened in the Sonoma update.
You need to select a different mode.
Even better would be to use a device on macOS that can use the Airdirect mode or act as a bluetooth midi device.