Under Biscuit mode, check the MIDI filters (see page 28 to 30 of the Biscuit User Manual).
Filter nr 6 is the “receive note” filter. It should be permanently on.
You’ll also have to match the MIDI channel (page 29) of the Biscuit and your DAW.
When it’s set (both channel and midi filters), you can go back to Der OTO mode.